How to change a waterproof light?

[dennis99ss]

We built a house and had can lights put into the bathroom. While the lamps above the sinks, hall to the closet, and entry into the bathroom are just regular floods, the lamps that are above the tub, and next to the shower, are waterproof. They appear to be regular can light fixtures, but have a glass cover which is flush with the ceiling. The glass spins, but does not come off. If I try to change the bulb without some info, I can envision a ceiling repair bill being necessary because I pulled the fixture out of the ceiling.

Does anybody have one of these? Does anybody know how to get to the bulb to change them? I hate to call out someone to change a light bulb. (besides, I would look like a girlie man if I can't change a light bulb.