I am the least mechanically inclined person I know....and I was able to take apart the back of the switch and see how the rubber boot & spring work. My rubber boot dry rotted and broke, causing the contact to not be made when I stepped down on the pedal. Replacement piece is like $2.

Just a warning though, it does take some patience and small fingers (neither of which I have) to do the job. My only suggestion is use a magnetized screwdriver for the small screws on the backside of the switch.