The title may not be the best explanation of what I'm asking, but basically, my killswitch is on the right side of the guitar, so when I'm playing it, it's underneath the strings, but what I'd like is to move it to the otherside of the guitar, so it's above the strings when I'm playing. Is that possible to do if I took it to a repair/mod shop?
It really depends on the guitar. As long as you can route a cavity for the switch, drill a hole for it and then drill a wiring channel through to the pickup cavities, it should be grand.
As MS said, it should be easy provided the body cavities allow wiring channels to be run. No problem at all on a strat type, maybe a bit more so on a Gibson style. It would be DIY for me.