To diy install aluminum windows several steps must be followed to insure that the window will function correctly. First, inspect the window. Make sure it is the right size and shape. Un-bend any bent corners. Make sure there are no cracks or other damage to the nailing fin or any other part of the window.
Make sure your window is square. If any of these are not correct do not install the window as it will cause problems after and during installation. Next you should prep your window for installation. Remove any shipping materials from the window.