I completed the mirror replacement. It was easy. Just be careful and don't "force" things to come apart.

Guru's are correct. The computer must be changed to "Dimming Mirror Present" for the Mirror to not dim when in reverse or when turning on an overead light. But the mirror will still function correctly.

I think I found a trick to the Mirror Installation that maybe not too many people know about.

Many complain that the mirror is difficult to "pop" back in. But I found that there is a very small spring clip under the larger "tubular" sprint. I found when you use a large pair of pliers and push the pins of the large tubular spring "inward" this allows you to pull the small spring clip which will then "seat" in between a "notch" on the barrel shaft. In other words, it fills a small notch on the large pin. This in turn keeps the pin somewhat inwards and allows you to just gently push the mirror back into its socket easily. At the same time you push the mirror back in, the force of this pushes that small spring clip that you earlier left holding the large pin inward, out of the notch and back into its original place. I think this is what they do at the factory because it would be crazy to have the technicains building brand new cars stopping the assembly line because of this installation. So I think the Mirror Manufacturer sends the mirros with the small pin holding the large pin in place for easy installation. But this is just my opinion anyway.