Hey Morten
You should open the pedal and check what kind of switch is there..some of them have a duoble contact, I mean opposite state.Just solder to the other..very simple.I did taht to a Yamaha pedal, has just a simple metalic contact, I hade to reajust the blade into another position, it's still working after years!
If you send me a photo on viocaia@yahoo.com I can advise better.