Jayco caravan windows (starcraft) 1994 model

I have replaced the 90 degree internal bracket from the top corner of a window, if that is what you are referring to. (on a 1989 Jayco). The window had to be removed to do the job. I had to start by drilling out the two rivets securing the winding mechanism to both sides of the window. Once the window was free of its adjusters, I was able to slide the window out of its top fixing. There is usually a small plastic retaining plug arrangement in the ends of this track that needs to be removed first so that the window can slide out. Once the window is out, you can get it on the bench and get to the 4 screws retaining the 90 degree bracket. There are two screws on the side and two on top usually, and you can't get to the top ones until the window is out. When replacing the pop rivets you drilled out earlier, just carefully pull them up enough to do the job and cut the nails off with side cutters. If you overdo it, your heading for trouble. From memory, these rivets were fairly long reach, about 1/8 by 5/8".
I hope this is what you were after and that I've been of some help.
I'm a two finger typist and I've just about worn 'em out.

Cheers .......................... KP.