All the screws came out easy and there was no adhesive on the inner flange, which came out with little resistance. Once out of the way I could see that the lower stop tabs had broken off on the outer flange allowing the window to drop.
Careful in re-installing the window (real glass)setting it on the bottom tabs and slightly applying some pressure to inbed it into the putty tape of the inter groove of the outer flange,remmber that only the putty is holding the outer flange at this time so don't apply too much pressure or you'll pop the outer flange out.
During our last trip to Death Valley the old rack system ended up with some damage to it. So it was time to up grade the rack still using the good old milk crates. Pictures 27-32 are the new rack, a good friend of mine welded it up for me.