I have got the sunvisors that have a mirror and 2 lights under a flip-up cover. One of the bulbs isn't working.

Can anyone tell me how to get the mirror/light unit of of the sunvisor so I can get at the bulbs to change them, and what type of bulb they are so I can get some ones ready for when I take the sunvisor to bits?

I don't what to go poking around with a screwdriver and damaging anything if someone knows how to do it right.