How do you take off the whole assebly? Not just the plastic window but the whole bracket itself?

 

THere are too caps on the back. Pry them off. Then unscrew the two screws. They are phillips.

These pix MIGHT help:

The screw holding down the camera mount is the same screw I use to hold in the windscreen


You can see the caps just in front of the hinge parts of the bracket.