You will need to remove the light console to get to the mounting for the mirror. You will notice a slot in each of the left and right side lights, those will pop off easily with a small blade screwdriver. Be careful not to damage the console. Once the covers are removed you will see a screw on each side. These screws hold the console in place. Remove those and the console will come off (you may have to disconnect the wiring for the lights). If the mirror is loose at the connection to the roof, simply tighten the screw there, otherwise you will need to remove the mounting screw. I would suggest that if you have to completely remove the mirror that you work the pivot point back and forth to loosen it while you have the mirror off (thereby curing your other problem).

The mirror bracket is a bit more complex than you might think. On the side of the bracket that is against the roof there is a single screw that holds in place two (about 2 inch long) metal rods (about the thickness of a clothes rack). These rods fit under the screw holding the bracket together. Once you get this open you'll notice how this is designed to pop loose under pressure. I suppose this is supposed to loosen the mirror in an accident and prevent it from becoming a dangerous object.

Anyway......once you manage to get the two rods to fit under the screw, the mirror and the bracket will once again be a solid piece. Fit the bracket back against the roof, tighten the mounting screw, put the console back in place, hook up the lighting, install the screws to hold the console, then pop the light covers back into place.

It isn't exactly simple, but you get to see one of the hidden safety features of your ride.