Not sure how to explain how to remove the mirrors you have without knowing how they're attached. If they are epoxied, can you remove any inside cover to see if the window was scratched up---let's hope not. The windows are tempered and difficult to break unless you mar the glass. You can try a hard plastic wedge or a putty knife with Gorilla tape on the glass surface side to protect it from scratches. Heat works with some adhesives but be careful, you can explode the window if it gets to hot/concentrated in one area.
Here is how I install window mirrors using a thin sheet metal plate installed on the mount that gets slid under the rubber on the bottom and front posts. The rubber does all the work---the tape keeps the mirror from sliding back out of the rubber window seal. No glass mars and they do not fall off.
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