1.1 Push the inboard side of the mirror (closest to the car) forward so you can insert your fingers into the small opening between the outer edge of the mirror housing and the glass itself.

1.2 Gently pry toward yourself until the mirror glass pops off. It's a good idea to have your other hand close by so the mirror doesn't bang against the car and break or chip the paint. Note the orientation of the wiring connectors on the back of the glass. You'll need to reattach these later, but unplug them for now and set the mirror glass aside.

Taken from the OEM plus website before it went down.