I'm usually able to pop it out with a pocket screwdriver. Wait to remove u
ntil you have the new one so you can see where the clips are. There are tw
o main retaining clips, on in the front and one in the rear. You'll want t
o release the rear one.
To release the clip, slip the screwdriver (small round shank is preferable)
under the rear edge of the switch. Then finesse it around so that you've
slipped it down inside the door panel under the rear edge of the switch, co
ntinuing to finesse intil you push on the clip and release it.