How to remove headlight and wiper switch without breaking them?

All good advice but I will add on to it. Remember that the headlites will be fully on once you pull out and release the knob/stem part, so either gently push (stem) back in until 'click, click' the headlites and parklites shut off - as it would take a harder push to re-engage the stem tip, or better yet, remove neg. battery cable.
One other way to try to remove the round retaining nut is to use suitable needle-nose pliers, with one pointed tip in each opposing slot. Push in gently to keep the tips engaged and then carefully turn 'lefty loosey'. :)