Pull off any trim molding around the current installed panel. Some panels are hidden underneath a piece of magnetized trim molding. Use a piece of tape to pull back the molding.
Loosen and remove any screws under the trim piece.
Loosen and remove the handle screws and pieces.
Grip the end of the panel. Slide the panel sideways out the channel opening.
Slide the overlay panel into the channel.
Replace the trim piece and door handle. Replace and tighten all of the screws.