To remove condensation, light a match and blow it out. While it is still hot, poke the head of the match carefully through the film in each corner. The match will melt the film and the holes will allow the moisture/condensation to escape. If moisture is still present after 2 to 3 days, make more holes (2 to 3) in each corner.
The film used in indoor window insulator kits is heat shrink film that can be stretched and shrunk with a hair dryer. The film used in an outdoor window insulator kit should not be shrunk with a hair dryer (this could cause over-shrinking when sunlight heats the film). Additionally, the tape used in the outdoor kits is designed to stand up to colder temperatures.
The sheets of film used in the larger kits are cut after they are folded once, making it difficult to separate at times. The best way to separate the film is to make "tabs" from two pieces of tape to help pull the film apart.