when we lived in our 50+ aged shotgun in new orleans, we got that GILA window film. you buy an 'installation kit' that included: a wipe pad to clean the windows (but we had so many i used newspaper), the spray that you use to clean and apply film (we used 2 bottles for 5 wide windows), a squeegie, a plastic corner doohicky (an aide in trimming), and an exacto to cut the film. you cut the film to approximate size (you buy the film in a box of roll, different sizes), clean window, spray the fluid back on, peel backing off film, apply to window, spray more fluid over film, squeegie film on, then trim excess. i did manage to do a lot by myself, but it may go easier if it is a two person job, especially for larger windows. it seemed to help a good 5 degrees or more! good luck!

I used the GILA tint on every window in the house. I don't have any developed trees around to block the heat from entering. I have noticed a huge difference already.

The only mistake I made was starting downstairs first. As I got better after each window, so I should have started with the windows that aren't seen much.

Live and learn! But I love it and it makes the house look sharp and energy efficient.