Cut out the window with your tool(s) of choice. Remember to finish out the window hole with a file and sand paper to get it smooth and burr less.
Finished hole in panel
Cutting the plexiglass
Place your plexiglass under the hole in the side panel that was just cut. The window needs to be a 1/4" smaller all the way around for the trim to fit right. Using a 1/4"washer works great. Once placed, get a felt-tip pen and a 1/4" washer.
Placed plexiglass and 1/4" washer
Hold the plexiglass and side panel still. Taping it on opposite sides to hold it in place is a good idea. Run the pen around the inside of the 1/4" washer while pushing the washer against the inside edge of the panel. This will give you the correct spacing for the trim.
Marking the plexi with the washer
Cut out the window on the line you just made. Finish up the edges with a file andsandpaper till the line is gone. Peel back the protective film just an inch or two on both sides for installation. Use tape, if needed, to keep the film out of the way.
Finish plexi and film taped back