[Rockmonster]

I put those windows in my place.....If you have the room, frame the opening with 2xpt....nail the fins into those, wrap, maybe picture frame the window, I used cedar, cut out the thickness of the fin from the back of the trim, usually the thickness of the tablesaw blade...cut in head flashing....I also use silicone under entire fin/flange, we have very wet environment....if no room for pt, use idea from AW, but I'd be wary of chopping those off....gl