I've recently purchased a single humbucker, and plan to remove the 3 single coil, 1 volume and 2 tone pickup configuration in my stratocaster with simply 1 humbucker and 1 volume. However, all the diagrams for wiring this show 4 protruding wired from the humbucker (I assume to allow for splitting of the humbucker), and various combinations of earthing. Previously the earth was soldered to the pickup selector, however I will now no longer need this. The new humbucker I have has only 2 wires, and all I plan to do is connect this to the output, via the volume pot. How should I do this?
If you ignore the four conductor circuit diagram and treat the pickup as a single coil, I'm sure it will work fine.
Try looking at the Gibson example on Wikipedia's guitar wiring article, with the one humbucker wired to a volume and tone pot. (Note this diagram is more complicated than you need. You need to look at just one pickup and its volume control.)
One of the pickup's connections will be treated as earth and wired to the pickup selector as you have now, the other connection will go to one end of the the volume pot's track.
(Are your two pickup wires different colurs? It might give a clue which is earth and which is signal, though I'm pretty sure it will be fine either way.)
Here is the simplest diagram I could find. http://www.diyguitarmods.com/wiringillustrations/1HB-1V.jpg
The wire coming from your pickup will most probably, if not undoubtedly, have one thin stranded wire, the hot lead, surrounded by a mesh, the ground shield. This mesh wire can be pulled from around the insulation and twisted into a usable wire that you can solder.
In the diagram I linked, they are using the green for the shield and the red for the hot. The wires they have labeled black and white will be internally connected in your pickup and not accessible. But since you are using a two lead pickup, the colors can be ignored.
So basically, your shield wire will go directly to ground, usually the back of the volume pot will be used as the center for all the ground leads, and your hot wire will go to the potentiometer lug on the left when viewed from behind, as in the diagram. Center lug of the pot goes to tip of the jack, and the right lug goes to ground, as does the sleeve connection of the jack.
Take care when wiring! Pre-tin all surfaces and wait a bit between soldering the various components on the back of the potentiometer so as not to melt the internal plastic component.