How do you remove the mirror glass from the exterior mirrors on SLK or similar models?

Push the mirror glass down all the way to the bottom, then you can access the retaining clip that's on top. Use a small screwdriver or similar to pop off the upper clip. Then just pop the mirror glass off of the motor. To re-install insert the glass at the bottom first, and then slide up and push on the catches. Then re-install the clip over the motor. The mirror has a install position for the clip, position the clip over the top of the plastic tab on top, then bend it back down and under the lower notch to hold it in position.