Fasten the supports in place, taking care to place them on the thick door rails versus over a panel, which is not as substantial. Choose your screw length based on door thickness and depth of pocket hole (I used 2” screws).
- Size trim for the door – to – wall joint. I happened to have doorjamb material from another door that worked out pretty well for trim. Cut the trim to length.
- Clamp the trim in place and scribe the existing baseboard profile to it.
- Using a scroll saw, jig saw, etc. cope the profile in the trim.
- Install the trim using finish nails or drive screws from the inside.
- Cut a plywood panel to fit for the lid.
- Install the plywood panel lid with two heavy hinges. If your old door still had its hinges, these work great and they should meld nicely with the style.
- Remove the lid and mask off edges adjoining the door with painter’s tape and paint the trim, lid support, and lid.