■類似問題 https://www.audi-sport.net/xf/threads/mirror-repair-help.323366/
I had mainly asked for help in undoing the spring and clip that holds the main folding assembly together. A few ideas were suggested, but sadly none worked. The spring was just too strong, and I was just too scared. I guess this is what holds the mirror without vibration when the vehicle is in motion. First, I tried using needle nose pliers of two sizes to compress the spring, but they weren't small enough to really get in between the spring, and kept slipping. Next was GI wire. I threaded it through, and twisted the ends, but it just broke at the twist. Maybe stranded steel cable would have worked, but I did not have access to it. Finally, I threaded the thickest cable tie I could, and tried to tighten it, but it just snapped. Having failed to compress the spring, I was doubtful that I could reassemble it after removal. So, I decided to alter the plan, and make the repair with the assembly in place.
The black trim looks like it can be removed only after the assembly is separated. So there is no way to access the other side of the casting. I feel that this is not a part designed to be dis-assembled. It looks like a one way manufactured part. Thanks for the suggestion anyway. Hopefully, I won't have to use it.