The installation process of interior door trim is relatively simple. First, remove the old trim by prying it off with a putty knife. Next, cut the new trim to size and attach it to the door with nails or screws. Finally, fill in any gaps between the trim and door with caulk or sealant.

1.Begin by measuring the width of your door. You will need to purchase trim that is a bit wider than the door itself so you can create a nice, even border. 2. Cut the trim to size using a saw. 3. If you are using a standard door knob, make a hole in the center of the trim wide enough for the knob to fit through. 4. Attach the trim to the door with nails or screws.