Clean all panes of the window with a non-ammonia-based cleaner, and allow to dry for ten minutes.
Measure a single pane with the measuring tape. Most residential windows have eight or twelve panes, so measure one pane for width and height.
Cut a section of window tint film to lightly larger dimensions than the window pane. It will leave a more professional look if you do one pane at a time. The window tint film should be about a quarter inch larger than the window pane on all sides.
Spray the pane with water, and daub up any excess from the bottom. Peel the clear plastic backing from the window tint film, and apply the glue side directly to the window glass quickly. Position the film while it is still saturated.
Squeegee the film gently from the center to the each edge to remove air bubbles. As the film begins to dry, apply more force to get out all possible air, and spray the film with more water along the edge if the bubbles won't come out easily.
Allow the pane to dry for about ten minutes.
Repeat Steps 3 through 6 on the remaining panes. Once complete, allow the film to set for 12 hours before cleaning with a non-ammonia-based cleaner.