I'm replacing the caps on the mirrors, and I've found the posts for doing the side mirrors, but I have not seen anything about the rearview mirror inside. Are there any tricks to this? Does the old cap come off, or does the replacement cover it? I've got the plain old mirror w/o Homelink.

 

The replacement inside mirror cap covers the existing cover. The replacement just kind of snaps on and has double sided tape to keep it in place. It's a quick and easy job. The cover does come with instructions but everything is quite simple on the plain mirror.