Today I was fixing some stuff on my car.. I finaly fixed the moonroof shade, it now moves again.. But then I decided to fix the hanging Vanity light/moonroof-motor cover.. After I pull it off I notice that the bracket is still on the roof. After some inspection I realize that the brackets that hold it on are/were glued to it. Now I realize why that '90 SHO had a moonroof-motor-cover full of glue. I decide to use some CLEAR RTV to make the bond then I get some clamps and clamp it down. At the time of this writing the clamps are still in place. To take off and put in the Vanity light/Moonroof-motor cover simply remove the vanity light lenses and unscrew the front brackets screws and tilt the front down then push up and it'll come out.
If anyone wants a step by step or some closer detail pictures ..say so.