I tried prying the mirror out of the rubber gasket like others have posted, I found there was too much pressure on the glass and felt like it was going to break. I then pulled on the rubber gasket with the glass still in it and with a small screwdriver, pried it out of the chrome housing. Every .5 an inch, I put the screwdriver in between the rubber/chrome and slowly pried the rubber nub out from under the small chrome lip. The mirror and rubber gasket came out pretty easily. Tighten the 10mm nut and test how tight you want your mirror. Put a long side (top or bottom) of the mirror/gasket nub into the chrome housing and lightly press it in while working the rubber nub into the chrome housing with a screwdriver till its in.