I learned the hard way on how to get the glass off. Luckily I already had purchased a pair off a junker. The glass has attached clips that clip into the face of the adjuster motor (for lack of a better term).
(link to image of face of adjuster motor on site muzak posted)
(link to glass)
To remove the glass, push the bottom of the mirror in (which inturns pushes the top out) and then "slide" the glass upwards. When I broke mine apart I found that at manufacturing they actually stick a little glue in there for good keeping. I literally had to use a flat bar and pry pretty hard for it to pop out.
If the glass is out you set the glass with attached clips into openings and then you just slide the glass down which locks the clips in place.