We have what looks like a BROAN 678, 679 and 680 Series installed in our bathroom. I cannot determine how to remove it to clean the unit or replace the light bulb, at least without my concern that I will break it off the mounts. See my picture showing that I can only move it about 1/4 inch on one side, with my hand, away from the ceiling. I have pulled, pushed, twisted, and nothing seems to work. Your video on cleaning such units is worthless (sorry) in this regard, since it proclaims that this is easy but it does not depict how to remove the unit from its mounts. Please advise.