[T77911S]

in the process of replacing mine now, also brick.
I let them come measure just because it is their dime if it is wrong although I did measure for the 2 in the garage and just went to home depot to get them. (inserts). its not hard.
he measured my 32x36 windows small, at about 31.626 and 35.625. this made it so the very edge of the new window was right AT the edge of the old frame. I would have liked a little tighter fit.

my problem is the old frames are in bad shape. paint needs to be removed/scraped. where I have scraped looks like crap so I have stopped and may just pay someone to paint.

taking old ones out is about a 10min job.
remove the inside trim around the window. don't break it.
raise the bottom sash to the middle and lower the top down to the middle. then just pry the aluminum frame out. mine where just stapled in. once the staples are out just pull the window in.

clean up around the old frame.

oh, pressure wash the out side really good first.

put a bead of caulk around the old frame and then install new window. do a dry fit first.
get some spray foam and fill gaps. caulk again inside and out

anyone have better ideas for scraping old paint off.