The title says it all. Should I change strings one by one, or take them all at once? Does this matter at all?
If I take all strings off, will it damage my neck in any way, because the pressure is released?
I have heard that it is not a problem taking them off all at once, and luthiers I have seen work on instruments will take all the strings off to clean the fretboard and alter the bridge. This website corroborates this theory, saying:
It's definitely OK to take off all the strings on any fretted instrument. It's just an old husband's tale that taking off all the strings will injure the neck or any other part of the instrument.
...your instrument would "rather" have no strings at all! Collectors and others who put their instruments into storage usually either remove the strings or detune completely.
It does, however, mention the practical benefits of changing one at a time; guitars with movable bridges are best done like this to stop the bridge moving. Also, if you don't have a tuner to hand, changing one string at a time makes it easier to tune up to the right pitch.
While I've read several different sources recommending not removing all the strings at once, I've never read a good reason why not, and I've always restrung by removing all the strings first. The main reason is exactly as you say: to be able to clean and condition everything under the strings. I clean the fretboard and body area, oil the fretboard, and even lightly polish the frets.
I've been doing that regularly on five different guitars starting in 1993, so I'm pretty sure if there were negative consequences I would have suffered them by now.
I think the main reason why people dissuade from taking off all strings is historical: on violin-family instruments as well as many archtop guitars, the bridge is not fixed on the instrument at all. It just stands freely on the top surface – normally held in place by the strings. But if you take the strings off, the bridge will fall, and you need to be very careful to place it at precisely the right spot again. Bowed strings furthermore have a sound post, and with all the string pressure gone that may also not be held in place firmly enough. Putting the sound post in place again is virtually impossible without the specialised tool that luthiers use for this purpose.
On modern electric guitars, as well as most (semi-)acoustic ones, there is no such issue. Only possible problem is that the neck may somewhat warp, because the truss rod (which normally counters the string tension) then forcefully bends the neck in the other direction. But I don't think this should ever cause long-term problems on a decent guitar; it may at worst result in some time where the guitar doesn't hold tune as well as if you had replaced the strings one by one.
I remove all strings at once. Like Brian I don't see how this could damage the guitar but that's not to say I'm doing something that I shouldn't - all I know is it hasn't harmed any of my guitars in all the years I've done it that way.
And as a small digression, I actually take advantage of having all the strings off the guitar as a rare chance to really properly clean some hard to reach areas e.g. all around the pickups, any dirt or grease around the fretboard etc.
EDIT: Just seen your update Jimi :) I suppose a lot depends on how valuable your guitar is whether you're concerned over the big change in tension from strings on to string off. You could probably still perform a rigorous clean with only one or two strings off at a time to maintain the bend in the neck.
Taking them all off at the same time isn't a problem so long as you detune the string before you cut it... This may seem rather obvious but I've seen it happen far too often. By detuning you can lower the tension in a safer manner for the guitar, then clip and continue with your restring. BTW. Getting a good cleaning in can be especially important for people with high acidity in their skin oils.
The main reasons have already been mentioned, but to elaborate with a few practical tips:
The tension of the strings is counterbalancing tension of the truss rod, and when string tension is removed the truss rod is "free" to bend the neck. While it's extremely unlikely that a guitar that was correctly set up would break from removal of string tension, the simultaneous removal of several strings may snap some of the remaining ones when the remaining string tension is insufficient to counteract the truss rod. If removing all of the strings at once, loosen the tension on all of them a bit first, and then remove them starting from the highest string (the one most likely to snap)
Also, when re-stringing from scratch, it takes several passes of tuning to reach the correct tension (the first ones tuned will be out of tune again after more strings are tensioned), so it's generally faster to replace strings one by one.
Some guitars (e.g., archtops) can have a floating bridge, which is held in place only by string tension. Removing or loosening too many strings causes the bridge to move, and repositioning it can be finicky and requires intonation to be set up again, which makes the whole operation considerably more difficult than just changing the strings should be.
On such instruments I try to clean the fretboard with the strings still in place: a cleaning cloth can be inserted between the strings and the fretboard, and if done with the old strings in place it doesn't matter if the fretboard cleaner is bad for the strings.
Alternatively, one can remove the all but the highest and lowest strings to create an opening in the middle (the highest string should be loosened slightly before removing the others, otherwise it may snap when the truss rod pulls it tighter). It may still be a good idea to lightly tape the floating bridge in place as it may not be be held perfectly still by just two loose strings. Again, fretboard cleaning is best done with the old strings holding the bridge so it doesn't matter if fretboard oil/cleaner goes all over the strings as you'll replace them after installing new middle strings.
On some guitars (e.g., many Les Pauls) the tailpiece is also held in place mainly by the strings. It is very simple to replace (since it will automatically be correctly positioned when the strings are installed), but I thought I'd mention it for sake of completeness – it may be surprising (and annoying) if the tailpiece unexpectedly falls off, and it might conceivably get scratched (or scratch something else) in the process.
Taking all six strings off at once creates a sudden decrease in tension across the neck of the guitar. The truss rod could even be damaged if they were heavy gauge strings. Certainly, this rarely, if ever, happens. Nevertheless, such abrupt changes as caused by the tensional shock of releasing all strings at once are not good for your instrument, especially the neck. (Imagine what happens, not just to the band but to your finger, when you released a stretched rubber band.)
Thus, it is recommended you change the strings one after the other. The only disadvantage of this is that you will not be able to have unobstructed access to the neck to give it some thorough cleaning. Prolonging the life of your instrument should be a priority, though. This is stuff I've read in several books and probably what a luthier would tell you, as well.
When I change my strings, I always change all of them in one sitting, unless I've broken one in performance and need to replace it on the spot. However, I remove and replace them individually, beginning with the low E and working up to the high E. This is true of both my electric and acoustic guitars (including classical). At least for my ES175, this is for practical reasons: I don't want the floating bridge falling off, making me re-intonate the thing. For the others, I'll only remove all the strings simultaneously to do maintenance: fretboard dressing, polishing, and so on.
As for whether you'll damage the guitar's neck removing all the strings at once, I don't think you will. I have, on occasion, removed all the strings from my 12-string (see comment on maintenance), without problems. And, as others have said, luthiers do this all the time.
Surprised nobody has stated this yet, but you do NOT want to remove all your strings at once on your guitar if it has a floating bridge (Floyd Rose, EBMM JP, Kahler, etc.). Those require a '1 by 1' string replacement to maintain tuning/proper setup.
If your bridge if fixed, feel free to remove all the strings at once. Don't just cut them with wire cutters while they are tuned though...detune all your strings, and then remove them. Any major sudden tension changes to the neck will cause irreversible damage to the truss rod.
Some instruments are held together by string tension. The bridge of archtop guitars is held there only by the strings, and the neck and pickups of the Mosrites that Johnny Ramone used were held to the body with string tension. (No, I'm not sure how, but read a story where a guitar mag journalist was asked to do this for Johnny when he was researching the story.) In these case, change half of 'em (the top half or bottom half, probably) then the other half.
Otherwise, I don't see how it would matter.
I fully agree with Todd Wilcox, but I'll try to open the subject a bit more.
The main argument why different sources tell you not to remove all strings at once is because the neck is adjusted to be straight by matching the tension between your strings and the truss rod. If you remove all strings at once your neck adjustment is off because you just removed the countertension. Most necks are made of wood, which as an organic material is prone to warp and "live" under varying conditions (humidity, temperature, tension, etc.). Thus by replacing strings one by one minimizes the tension variable while replacing them.
According to my experiences if you remove all strings at once for an half hour or so while cleaning and maintaining your fingerboard, the long-term effect of the inevitable tension in-balance is neglible or even non-existent. Afterall wood isn't so fast in changing its shape under varying conditions.
However, I would never ever leave a stringed instrument un-stringed for no longer than necessary.
Saying that taking all of the strings off at the same time damages the guitar definitely sounds silly - guitars are made to take stuff like that.
By changing strings at the same time, you get more consistent tone, as they're all at the same level of wear. Additionally, you may want to change all of the strings even if you haven't broken any, to restore some tone if they've undergone excessive wear.
If you change one string at a time, you get more awkward tone and playability (not a huge difference, but it's definitely there). Additionally, this makes everything more difficult to organize (what if you break two G strings consecutively? You have to throw away a bunch of perfectly good strings).
Thus, my answer is: change them all at once.
When we make bows of straight sticks of wood, we spend a long time using an instrument that pulls the bow into the "final" shape. You take it up one notch, then wait for a few hours to a few days, then take it up another notch until you finally get it to the shape you want. There's a reason bowyers didn't do this all at once.
Sudden release of tension on a dry piece of wood can damage it.
I solved this just by using a leader string system. Detune them all except the middle string, having it at the lowest tension where it still floats. remove the other strings and clean fretboard. Put strings on either side of the leader string and tighten them just enough to hold that pressure when you remove the lead. clean fretboard under that string and replace string, add the other strings.
When you have a xx00 dollar instrument, you don't take a laissez faire approach to it.
Firstly, on a technical level you should always change your entire set of strings in one sitting versus changing only a string that breaks or sounds bad unless you're in the middle of a gig, practice session, etc; but afterwards change your strings starting with low E (6E) and then A & so on.
Secondly, to address everyone's concern about being able to clean & oil the fingerboard I would suggest taking the time to reduce tension a small amount & equally ie same number of peg turns for each string (a great deal is not necessary) and clean your fingerboard and as you will find you can move the strings to clean it fairly quickly if you have been maintaining your guitar properly and once clean oiling is easy; who cares if you get a little oil on your strings? You're changing them anyway.
To clean the oil off of the strings take a dry cloth (flat, not bunched) & slide it under the strings & then just fold cloth over top of all 6 strings & run it up & down the fingerboard, then do each string individually to be on the safe side.
Before changing the strings I would re-tension them but you shouldn't have reduced the tension much in the first place.
Third, change your strings one at a time, loosening the string so that there is no tension at all before removing, fitting the new string and retensioning before moving to the next string. The important things to remember are that you should check with your manufacturer on oiling (but always keep it clean), don't guess if you don't know, and most importantly, whether just changing strings or cleaning and oiling your fingerboard, do it one string at a time.
All guitars are different - don't generalise, as depending on design, you could really screw up your guitar's setup or damage it. Those of you with stop bars would cause the bar to fall out and damage your guitar if you changed all the strings at once.
Yes, many professionals change all six at once for a concert, with roadies using impact screwdrivers and other electric tools, but they also use masking tape to hold the stop bar in.
Remember it's your guitar. If you care about it speak with Manufacturers, Luthiers, Tech Specialists; Just changing the gauge of strings can screw up your intonation.
I have removed all strings at once (after tuning them down to slack) since 1972. It's a great pportunity for a deep clean too! I have also cut strings once slack to avoid damage when puling thru the bridge, body, etc. I have never had problems with any guitars doing it this way. I do tend to tension the strings across the board gradually when tightening new strings but that probably goes without saying. It's a lump of wood and really the tension isn't so great to be honest...
There is absolutely no danger to removing all the strings you just need to stop the floating bridge with a block or something. If the truss rod countertension was enough to damage the neck wood it would do so every time you make a dive with the floating trem which effectively reduces string tension close to zero.
Just make sure you loosen up the strings slowly and all together meaning don't take out the first 4-5 leaving the high E to take all the load from the countertension of the bridge and/or the neck.