The complication of the procedure depends on the model of RG. If you have a scratchplate its nice and easy...simply buy a new one with h/s/s cut outs. Probably your best bet to get in contact with
Jeannie pickguard as they will make what your looking for.
If your RG is rear routed and therefore has no scratchplate it becomes somewhat more complicated... You would have to fill the humbucker sized hole and re-route for a single coil. If this is the case your probably best to talk to project guitar or someone of similar guitar-mod-knowladge

hope I helped and good luck
-better shred than dead-ANDY