[Rwillia4]

Depending on the diameter of the hole...goto home depot or mcmaster.com (page 3624) and purchase a grommet hole cutter. The key is to oversize the hole a little bit to keep the padding from grabbing the drill bit. This totally depends on the overlap of the switch.
If there is not enough of a switch lip it is a little more difficult. you will need to cut a X a little smaller then the diameter of the hole. Purchase a pipe with the inner diameter a bit bigger then the diameter of the hole, I have used copper or aluminum in the past (mcmaster.com). Cut the pipe to a length shorter then the drill bit length, 2" is usually good. You should be able to stretch the leather and the foam "tabs" of the X around the outside of the pipe, hold it flush onto the dash surface. Drill through the tube, be careful not to slam the chuck into the pipe once it cuts through or the pipe will spin...