have a light fixture in the shower with a (hopefully just) burnt out bulb. I got the metal cage (held on by two screws) off but can't get the glass cover off. The whole thing rotates 360 so it's not screwed into a box or the ceiling. Might be springs or something holding the fixture base up There appears to be a rubber ring around it but I'm not sure I should get at it with anything. The glass doesn't move at all. I can hold the metal base and give the glass all my might, doesn't budge at all. Google was of no help Pics attached. Thanks in advance.