Use a screwdriver to remove the screws holding your old carpet trim in place. Pull the old carpet trim off the floor and away from the door frame. Set it aside.
Measure the width of the door frame. Use a pencil to mark this measurement on the new carpet trim.
Place the new carpet trim in the door frame. Use a pencil to mark the width of the door stop on either side of the door. Remove the new carpet trim from the door frame.
Cut a notch out of each corner of the new carpet trim with a saw. The notches should be the width of the door stops and about 1/2-inch long. Use a tin snips to cut the notches out of a metal carpet trim.
Place the new carpet trim in the door frame. Make sure the notches you cut are positioned over the door stops. Secure the carpet trim in place with the provided screws.