The switches simply pry apart with a small flat head screw driver.
However you need to be carefull not to let the springs, ball bearings and contacts fall out everywhere.
Once open it looks abit daunting, but clean all the contacts up, reposition everyting and give it a go.
Also check the fuses underneath the passenger seat. Acces is via the rear seat footwell. You should see four 30 amp fuses, two of mine had burnt out.