The link below is to a current string regarding removal and replacement of side windows in aluminum frames. On our OA, the windshield glass is also glued into the frames, just as the for the side windows...exactly the same general frame construction, but without the additional track for the sliders. I suspect your aluminum frames are similar if not identical.
As I mention in the attached string, you can buy a wood carving knife kit at Harbor Freight that includes a couple of long thin flexible razor type blades. Those blades are fragile, so you have be careful not to snap them off. The kit is $15. Going slowly, I expect you could cut the bonding on a windshield pane in an hour or so. Or you could hire a glass shop...$80/hour in the mid-west.
I would not attempt to remove the aluminum frame from the boat structure unless there's a rot problem, and even then I'd try to find a way to reseal them.
http://www.trawlerforum.com/forums/s...mes-46470.html