Forgive my poor camera skills, but here's an attempt to help. I was able to remove the cover by the following steps:
1> Push mirror toward *front* of car
2> With a firm grip on the mirror (the spring is very tight so be careful),
locate the "metal band" that is oval and has a very small clip nearest the
apex of the band. See pic below.
At the
very bottom of this pic is the tiny metal square tab that all you need to do is push forward to loosen the entire oval metal band. Be ready to let the entire housing return to it's "normal" position once loose. The cover should slide right off once that's loose.
3> To re install the cover, gently slide it back over the arm assembly until
you hear the two metal clips click and catch the plastic cover. See below for image of backside showing clips:
Hope this was helpful.
barkford