Agree with Thebern. GREAT emphasis is on the word CAREFULLY. The switch contains a couple of springs and a small ball bearing, besides some other small parts. If you open the switck back cover the springs will propell all the parts, especially the ball bearing (which also rolls to places you won't believe), into all four corners of your garage.
Try to disassemble it inside a clear ziplock bag, at least you limit the flightpath of the pieces...