Replacing aluminum basement windows set in concrete
 

I need to replace the windows in my basement. They are aluminum framed basement windows that are set into my poured foundation. My question is how do you get the old window frame out? I don't see any screws holding it in place. They look kind of like storm windows. I am guessing I have to pry the old frame out. If anyone can help me out that would be great.

Can you leave the frame perimeter in and cover it with wood? Then this becomes the rough opening for the new windows.

Otherwise you might have to rent an electric jackhammer.

Cut and remove entire frame & window. Start new with treated window "buck" if you have the room or install new window frame leaving a 1/4" gap around for foam and caulk finish. New windows can be installed with nailing fin to "buck" or jamb screws or clips to fasten to block or brick.;)

If I cut the window frame, will it pry out?

Yes, It should pry out. It might have a few screws or nails through it but it should pry out. Some builder put screws or nails in them and then set it in the mortar or concrete but its nothing to get them out once you cut it. A small tip, cut in the middle of top or bottom frame then pry out in pieces. makes it much easier. ;)