I have never read/heard of any easy way to remove the glass from the frame, would also like to hear if there is one.
When I did this job, I took the vent windows out of the doors, which is quite a lot of work. You could drill out the rivet at the top pivot, and pull the glass w/frame out, but then you will need new rivets. The ones I bought from west coast metric and rocky mt a few years ago were both the wrong size. I had to go to lowes or home depot for some stainless steel pop-rivets, and even they were slightly oversized thus requiring some drilling of the pivots.
Once out, if you pull the frame apart slightly (don't kink/bend it), that ought to be enough to be able to get the glass out ( but it will still require some effort). Buy new seals of course when re-installing the glass.
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