It happens everyday, by accident, heat, anger, or faulty installation, but your rear view mirror and come off. It is only glued to your windshield and can easily be knocked off because of the leverage it poses. Getting your rearview mirror back on is one of the easiest jobs for a auto glass shop and they can do it for you in a few minutes. So you are saying if it easy, why not do it myself. Most people could but the cost of doing it yourself is going to cost more than taking to the glass shop.
Driving to the auto parts store, buying a adhesive kit, you will need to buy a razor blade to scrap off the old glue, buy a tape measure and taking the time to measure out the position, buy a allen wrench to take apart the mirror from the plate that attaches to the windshield applying the adhesive, you will also need masking tape, (more money), a grease pencil to mark your position. The adhesive kit will come with a vial of super strong glue and a vial of accelerant to help the glue cure very quickly. This is another problem, if you do not apply the mirror soon enough it will not stick, but on the other hand apply it too quickly and it will fall off. After all you do not apply rearview mirrors for a living, how would you know when the glue is ready, right? Temperature, humidity, sunlight, angle of the windshield all play a role in when and how to apply to mirror once you have put the glue and accelerant on. Oh and don’t forget, it you get the glue on your hands, seat, carpet…..good luck getting it off, this stuff is designed to stay on.
Many do it your selfers try to attach the mirror to quickly and end up pulling the plate off and have to start all off again. Ok, this doesn’t sound that easy and it is not unless you do it everyday. American Auto Glass does it every day for customers all over Cincinnati, Northern Kentucky, and the TriState area. They can have you done and ready to go quickly, at a cost that will be much less that buying everything you need separately.