Ok, I finally finished replacing the mirror. (First I had disconnected negative battery cable, then gently pryed the mirror sail cover from inside the door). Then I lifted up the 2 screw covers (one under door release handle, and one inside door pull cup), and removed the torx screws. I had to take the door panel about half way off because the mirror electrical connection (wire) does have an anchor point (a plastic snap) to the metal frame just under the door panel, and the electrical plug has a very tiny press clip you have to squeeze to disengage it from the control module inside the door. I had pryed up the window control module to give me access inside the door panel without removing it, to reach the electrical plug with my hand, which I did, but because it was the third plug in the row of plugs to the farthest left, there was not enough room for me to disengage the clip because of the tiny snap clip that has to be squeezed just right to release the plug. Trying to take the old mirror apart to leave the electrical wires for the new mirror did not work because the complex way the electrical wires are run through the mirror assembly, I figured I would tear up the new mirror trying to run them in place, even if I figured out how to release them from the old mirror (though they do unplug easy enough from the two connections inside the mirror, but that's a mute point.).
So I finally got brave, and tried (stupidly) to pry the door panel off in the dark ( I should have had patience and waited until daylight). I first used the thinner trim tool and laid on the ground under the door, trying to use the trim tool and door frame as leverage to pry the door panel out. It wasn't working that great, and this morning I noticed lots of really tiny chips in the paint right at the line where the door panel touches the metal door frame. Either they were already there, or I did that using the trim tool incorrectly, and in the dark not realizing I was doing that. But not a big deal because they were so tiny and at the very bottom of the door they can't be seen.
Then I remembered reading somewhere online someone suggesting to use either a trim tool or a paint scraper and start at the bottom corner (in my case I chose the bottom left corner closest to the mirror since that was the side I needed to work on), and pry the door panel while lifting up. So this time I used the wide, flat ended trim tool, stood in front of the door and carefully pryed the door panel out (holding the tool against the panel instead of the door frame), and pulling out(instead of laying down and using the door frame as a leverage for the smaller trim tool), until I heard my first wonderful snap of a door clip releasing. I continued working the left side of the door up to the mirror until all clips on that side were released. I was using a smaller trim tool to try and reach under the door panel and release the plastic (mirror) wire anchor from the door frame when I realized each pry I was also loosening the door panel more and more (I was inadvertently lifting the quarter inch plastic lip of the top of the door panel up over the window's ledge, loosening the door panel more and more, giving me more room to work). Replacing the mirror, then, was a snap. Before putting the door panel back on, I reconnected the negative battery cable and made sure the electrical mirror control worked. Then when putting the door panel back on, I made sure each of the plastic door clips was aligned in their respective white clip holes (one was wedged sideways off center) before snapping the door panel back in place (once every plastic fastener clip was straight, I used my hand to gently pound around the edge of the door frame until I heard each tiny faint snap of each clip securing to the door panel tightly against the frame). Oh, and I never broke any of the snap clips, to my surprise. Once I realized what I was doing, the whole job was rather simple. Now I have confidence when I decide I want to change the door speakers, unlike before
Here is a link to a picture of what the door panel on my DGC pretty much looks like looks (as far as the clips being in the exact same place, but didn't take time to compare smaller details) (and mine is gray). It shows the location of each plastic clip.