depending on what MY you have, you either have a one piece "horse shoe" surround or 3 individual pieces (2 wings on top of overall surround) of trim surrounding the center stack / radio / HVAC controls. In either case, the trim easily pries off so you can access what's behind it (i.e. your fallen switch).
Use a trim panel remover, small putty knife or butter knife from your kitchen and cover the business end w/ electrical tape to prevent scratching the trim. Pry up underneath the right hand corner of the trim piece. Apply even gentle but firm pressure to get the corner to release and then work your way up until it's all free. If you have the 3 piece, you'll just need to pop the wing. If you have the one piece horseshoe you'll need to work your way around and release the whole piece. Once it's out, you'll be able to access the back side and loose switch.
Here's a picture of a 3 panel trim surround:
