The 1991+ 700/900 mirrors use four pairs of fingers to hold the mirror to the adjusting mechanism. I start by pulling the mirror out, at the outside, and using a flat blade screw driver to release the hooks on the ends of the fingers. You must keep tension on the mirror as you do this. Then, when you have both pairs of finger tips (hooks) released on the outside of the mirror, insert something (I use a piece of wire) to keep the mirror from snapping back into place. Then pull the inside edge of the mirror out and do the same.