Measure the size of the raised-panel area and write down your measurements.
Trace these measurements onto the back of the sheet of plywood with a pencil.
Cut the plywood to fit using a circular saw. If you have a large sheet of plywood, have a friend hold the end while you feed it through the saw to make it easier to handle.
Measure the size of trim pieces needed and cut them to fit, leaving an extra inch on both the top and bottom, using the circular saw. Turn the wood trim so it is angled into the saw blade at a 45-degree angle and run the trim through to make your edge cuts on the top and bottom of each trim piece.
Sand the plywood panel and trim wood lightly. Apply a coat of wood stain or latex paint that matches your door. Let this coat dry for four hours. If staining, sand the wood again and apply one coat of polyurethane. Let this dry for six hours before proceeding.
Remove the door using a flat-blade screwdriver and place it on a flat surface. Apply wood glue in a zig-zag pattern to the back of the plywood and the surface of the door. Press them together firmly. Clamp the plywood into place with a cushioned wood vise.
Apply wood glue to the back of the trim and the door and press it firmly into place. Allow the glue enough time to cure, usually between eight and 24 hours, before hanging the door.