So, with all the guessing from small upper piece and lower piece, I admittedly was getting nervous using my trim tool to try and remove the upper piece. So I fold the mirror over as far as I can and I take my trim tool and wedge it in the hole with the neck of the mirror itself and pry. I notice that the whole plastic cover is actually "squeezing" or moving together. I then decide to put the trim tool against the glass on the bottom side of the entire plastic housing and just like that it pops out, I then work the trim tool around the housing and pop it all off from the windshield in one piece. I then, turn the mirror itself 1/4 turn to the left and the mirror comes off its base against the windshield. Pictures below to reference. Takes about 30 seconds to remove it all then unplug the wiring harness install your mirror tap or connections for whatever you're putting up there, radar, dash cam, gps, etc.
For the second part of re-installing you need to lift everything up into place and get the mirror ready to re-install on its base on the windshield. Here you need to find the correct orientation so that the mirror alignment neck is facing 9 o'clock, then press the neck into the spring tension base and turn clockwise 1/4 turn to the right and it will immediately set into position. Once you've finagled that together just push the entire housing back into the windshield and pop into place. Pictures attached. I did have to get a tiny small steel L shaped pick to press down into the wire housings as my wire tape would not go down into the housing, extremely tight fit. Once I created a small enough gap to allow the mirror taps to fit, I pressed the wires into the red/white (hot) and black (ground) and put it back together. The entire experiment took about 30 minutes but once I discovered how to do it, I can assure it, it won't take 5 minutes to do the entire job. Hope this helps.
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