To remove the cover housing without breaking it:
Pry both light lenses out. Insert a small screwdriver between the center-facing edge of the lens and the housing and pry the lens downward. It will pop out. Do both sides. If you're lucky and the plastic is not too brittle, the tabs won't break.
Remove both light bulbs by pulling them out of their sockets.
Under each bulb is a Phillips-head screw. Remove both, don't loose them.
Drop the front of the cover a small amount, then pull the whole assembly rearward to disengage the rear "hooks" from the inside of the roof panel.
With the cover dropped, you can disconnect the electrical connector and take the cover into the house to repair.
I used a big old glob of JB Weld on both sides of the switch to secure mine back in place. Make sure you thoroughly clean the surfaces with alcohol first so that the epoxy-based glues can adhere.
Put it back together and use the switch.
Steve