Pre-hung doors are rather easy to install; however, removing them does pose quite a challenge. Because pre-hung doors may have been fit in place perfectly with nails, shims or screws, you will find that a saw with a metal-cutting blade will speed the process along. Be sure to follow safety guidelines and wear goggles and gloves if you so choose.
Step 1 — Remove Trim
You have to remove the trim from the door with a pry bar. If you are planning to reuse the trim, make sure to remove it gently, one piece at a time. There will probably be nail holes that you want filled. Once you have the new door hung and are ready to reattach the trim, you can fill the holes with wood putty and paint over them.
If you are planning to replace the trim, you should still remove it gently. The old trim will serve as an excellent template for the new trim. Because the measurements will be perfect, you will be able to cut your new pieces precisely.
Step 2 — Separate the Door from the Frame
In order to separate the door from the frame, you will have to remove the hinges. Then check for the long screws that run all the way through the frame. Remove these screws. You should take great care in lifting pre-hung doors from their frames. Depending on the style of the door, it could be very heavy. Slowly move the door from the frame.
Step 3 — Loosen the Doorjamb
With the door out of the way, you gain direct access to the doorjamb. This will probably be the most difficult portion of the job because of nails and shims. Most of the nail will have been pushed down and covered with putty. Your best bet is to free the jamb by cutting it out with a reciprocating saw fit with a metal-cutting blade. The saw should be able to cut through the nails with ease. If you know that the door was set with screws, the saw will work but will take considerably longer.
Step 4 — Remove the Doorjamb
Push the doorjamb out of the opening. Be careful not to stick yourself with nails or sharp edges. If you plan to replace the threshold, now would be the time to do it.
Before you leave the jobsite or install new pre-hung doors, you will want to make sure the opening is free of nails or sharp objects. If you see any, try to remove them or countersink them with a nail set. If you see old insulation or hardened caulk, you will want to remove that as well.