Inside rearview mirror came off due to excessive heat. I can not get the metal plate (mount) off the stem to reglue to windshied. Should be a set screw or something hidden?

The piece that is on the glass is glued on with an ultra violet cured adhesive, or a two part epoxy adhesive. The last one I did was cured by the sun in 24 hours (mix, set and cure).

https://www.youtube.com/watch?v=8IBp0Pkoa24

Gluing it back on

https://www.google.com/search?q=fixing+rear+view+mirror+mounting+plate

Permatex® Rear-view Mirror Repair Kit - Canadian Tire

https://www.canadiantire.ca > ... > Interior Car Mirrors
Jan 23, 2022 - Permatex® Rear-view Mirror Repair Kit contains everything required for making professional quality repairs in just minutes Two part adhesive ...
Mount Style: Adhesive
Assembled Weight (kg): 1.00 kg
Assembled Weight (lb): 2.20 lb
Assembled Width (mm): 10.00 mm Rating: 3.3 · ‎$6.49

How to Fix a Rearview Mirror - NAPA Know How Blog

https://knowhow.napaonline.com > how-to-fix-a-rearvi...
Jul 30, 2020 - Most rearview mirror repair kits only come with the glue components, some come with a replacement metal glue-on tab, but you still need a couple ...

Permatex® Rearview Mirror Adhesive Kit

https://www.permatex.com > products > permatex-rearv...
Permatex's Rearview Mirror Adhesive contains everything required for making professional quality repairs in just minutes. This repair kit includes ...

Rearview Mirror Repair Kit - Princess Auto

https://www.princessauto.com > product
Home · Auto Repair · Chemicals, Adhesives and Lubricants · Adhesives and Sealants · Instant Adhesives; Rearview Mirror Repair Kit.

Any auto parts store will have a rearview mirror adhesive kit, follow instructions to the letter...... or it'll come off driving dow the road. Especially temperatures.

It may be held on by small set screw. (Allen wrench type) Or it just pops on and off, with effort.
To pop it off, hold the mirror as it would normally sit, and with that position in mind, you want to slide the metal plate down and out of the mirror clip, and you may have to pry on it a bit to get it started.

After you have reattached the plate to the windshield, you will have to apply almost the same force to clip the mirror back on.

Tips: Mark the location of the metal plate with a piece of tape on the outside of the windshield.
Make sure you clean the old glue off both the plate and windshield. Do not scratch metal plate.
Make sure you glue the plate on correctly. Do a trial fit on the mirror just prior to glueing.

Usually you can see a faint outline of where the mirror was last...BE CERTAIN to use the mirror mount kit, primer and all. Nothing else even comes close to holding..

They changed it. You have to slide the mounting bracket out the bottom of the mirror case.It's a tight fit but the mirror assembly will slide off, toward the roof. Once you have it off you will see a small slot on the bottom of the mounting bracket. Slide a small screwdriver in the slot and push toward the mounting plate (windshield). The plate that goes on the windshield should pop off. Hope this helps.

Just about every rearview mirror is now attached to the windshield with a special glue. Normally there is a metal piece that the mirror stem actually attaches too. To fix this yourself, you want to do is visit a local auto parts store and pickup a kit to reattach the metal piece to the windshield. Do not try super glue, it will not hold. Follow the directions on the kit for an easy repair.

use a special pad if you can get one or a new mirror ,do not glue it with epoxy type glues because the sun will expand it and then the windscreen will crack ,trust me ,got the teashirt here

Most mirror's have a small set screw holding them on the mounting plate, usually an allen head. You will need to get a mirror installation kit (glue) from a parts store. Most "chain" stores should carry them. What ever you do, DO NOT USE SUPER GLUE. The package should have clear instructions, just follow them and you should be fine.

Good Luck

the metal piece just slides off, either up or down.

Hiya...ALL factory-installed rearview mirrors are installed with different wires due to options.
About 6 different rearview mirrors are installed with those options such as On-Star, light, compass, and those features which use different wires....THIS CANNOT be modified with different rearview mirror....**for example, the Equinox owner attempt to pull out a factory-installed base rearview mirror and put in different one that has compass/temperature built into the rearview mirror**

However, the wires are located inside the front headliner which requires removing the sunvisor (and possible removal of interior plastic trim part at the left/right ends of the windshield) prior to pull the headliner down, and a small metal philips or torx screw is used to secure the rearview mirror onto the bracket glued to the windshield.

The best solution is to leave the original factory-installed rearview mirror in place.