After looking at a video which showed the mirror removed from the button, I realized that the hole in the center of the button would allow me to remove the T25 screw holding the retaining clip for the button along with the button. Once the button was out of the bracket it was easy to separate the button and the clip and reattach the clip to the mirror.
It looked like some of the mirrors that I saw in the videos did not have the hole that allows access to the screw. If you have one of those the most productive options would be (all untested):
Drill about a 5 mm hole (large enough to accommodate a T25 driver) through the center of the button. The material at the center is pretty think, about 10 mm, but since it scratches easily it would probably be pretty easy to drill as well.
Pry at 90° to the vertical axis of the button (that's where the clip is), on mine it was hard to get a tool in there, but the mirror bracket is metal so I think I would feel comfortable prying hard.
Clean the button and glue it to a scrap of glass or a piece of metal and the twist it off (by turning it 90°), then you have the problem of separating the button from the material that you glued it to…
This is the mirror as it looked, more or less, after the glue failed. The "button" has been cleaned and is sitting 90° CCW from the position it will be in when it is mounted. You can see the T25 Torx head screw through the hole.
The mirror with the button removed and the clip but back into place.
The mirror showing the back side of the button. The button is upside down in relation to the mirror. When installed the text (023) on the button reads right side up.
The process of reattaching the mirror was quite straight forward:
- Warm up the windshield, instructions call for 50°F to 75°F.
- Remove the old adhesive from the button and the windshield with a razor scraper. I think cleaned the windshield with denatured alcohol and sanded the button lightly to make sure that the face was smooth. My windshield had a black dot where the button went so there was no need to mark the location.
- Open the glass primer "wipe" and apply to mounting spot on the windshield. Allow to dry.
- Apply "one drop" of adhesive to the center of the button. The first time I did this, I applied four "little drops" around the hole. That was not enough and the button didn't adhere. So I started over and applied four "big drops" – each about the size of a grain of rice – around the hole. I figured that I wanted enough of the adhesive to fill and gaps between the button and the windshield.
- Lined it up with the dot on the windshield and held in place for 1 minute, I tried not to move the button at all once I pushed it into place.
- Waited an hour then attached the mirror. It took a lot of force to turn the mirror a full 90° so that it would snap into the clip. I was actually surprised that the adhesive would tolerate the strain, but it did.
The whole process was easier and faster than writing this up…