If you repeatedly lock your keys in the car, you may often have to break the small triangle piece of glass on the back passenger-side window. Taking the car to the mechanic to get the window fixed can be expensive and inconvenient. You can fix the window by using the right kind of glue to hold it securely in place. There are some preliminary steps that need to be performed before inserting a new window in the door.
Plug in the heat gun or hair dryer to an electrical outlet near your vehicle. Use the heat gun or hair dryer to heat the original glue inside the window frame until it is soft. The top will begin to soften, at which point you should be able to use the plastic putty knife to scrape off the glue completely.2
Spray the frame and glass with glass cleaner and wipe the surfaces clean with paper towels.3
Spread an industrial strength glue around the edges of the new window glass and wait three minutes to let the glue begin to cure before pressing it into the glass frame.4
Hold the new piece of glass in the door firmly for five to 10 minutes before letting go. Allow the glass to dry for 24 hours before opening or closing the door. The glue will fully cure in 48 hours.