If it's a pad sensor causing the problem then you can just trace the wire back,snip it off and then insulate it.It's just a single wire that runs to the pads,it makes a circuit to earth when the wire rubs up against the disc when the pads get low,so if you cut and insulate the wire it won't make connection and the light/warning will go out.
If the car has rear discs,check the pads on them too before messing about with the front ones.
