It isn't my intention to necro a post this old, but I was looking for information on how to re-install the mirror and control panel after servicing and just couldn't find anything. Anyone pulling the mirror out is probably going to find this thread so this may be the best place to put it. Here's what I did. I didn't expect it to work this well and hence, no photos.
There are threads (including this one) talking about how tough it is to re-insert the mirror assembly back into its frame. There is a pretty strong spring pushing two pins out and that pressure is what keeps the mirror in place. I put the thing in a vice and squeezed the two pins together. In the "middle", there are collars as well as the spring. I pushed a plain 2mm allen key up from the bottom of the mirror and set it between the collar and the casting on the drivers' side of the mirror. 2mm is about as much as you are going to get. I then backed off the vice until the collar was pinching the key. At this point, I have the drivers' side pin almost fully retracted and the passenger side pin fully extended while an allen key hangs straight down. I twisted the assembly into place and then pulled on the key while holding the assembly in position. Despite the pressure, the key came out easily and locked it in place. Honestly, from the time I "set" the Allen key in place until it was re-installed wasn't two minutes.
I then re-clamped the wires to the control panel and plugged them into their respective sockets. You can move the control panel towards the mirror, close to the roof and pretty much parallel to it. When it was close to that piece of trim around the neck of the mirror, I snapped that trim back into the control panel.
As opposed to removal, where you have to pull down the front of the control panel before the back, you can re-install it "flat", where all posts get pushed back up that the same time. When you snap the mirror-collar-trim back into the control panel, you are left with just enough room to ensure the wires are out of the way and snap it back in place. The only thing left is the cowl that goes over the rain sensor.
Hope this helps the next mirror-thread-searcher!