I just fixed my mirrors on Saturday. Many thanks to those who have posted the how-to's--very helpful! Once I got mine out, I took a little different route. Like most people, one or two of the "hooks" had broken off. So, rather than mess with the JB weld or zipties, I simply took a paper clip, cut it into a "J" shape with wire cutters to match the angle/profile of the missing/broken piece from the plastic hook mounts. Then I just took the paper clip and held it with some needle nose pliers into the flame on our gas stove until it was glowing red, then I just pushed it into the plastic bracket where the hook was broken. The paperclip heats the plastic and goes in a good 1/8 of an inch. I just let it cool for a bit, and then tried to pull it back out with the pliers--that baby isn't going anywhere!!
I also noticed that on the driver's side mirror one of the hooks was cracked but not yet broken off. So, I fired up my $9 soldering iron, got it nice and hot, and "welded" the plastic together. Took all of 2-3 minutes and it's strong as heck!
NP