I have an old Stratocaster copy and was thinking of putting a humbucker in it. My question is could I take out the two single coils and re-wire the guitar so that there is only a master volume where one of the tone knobs should be? Something similar to a Tom DeLonge Strat, like this picture
Yup. Just cut out what you don't need. There's really nothing simpler. Don't want something? Don't install it or remove it if it is already there.
your only problem would be the holes in your pickguard. otherwise, it would be perfectly fine