How do you replace a door casing? You can buy a kit that has all the pieces you need, or you can get individual pieces at a hardware store. You'll also need wood glue, clamps, and a drill.First, take the old casing off the door. The easiest way to do this is to use a chisel and hammer to pry it off. If there are any nails left in the casing, remove them with pliers.Next, measure the width and height of the opening where the casing will go and cut two pieces of wood to those measurements using a saw. Glue and clamp the two pieces of wood together so they form a rectangle.

How to Replace a Door Casing First, remove the old casing by prying it off with a screwdriver. If the casing is painted or stained, you may need to use a chisel or sandpaper to get it started. Then, measure the width of the opening and cut a piece of new casing to fit using a miter saw or handsaw. Make sure to cut it at a 45-degree angle so it will fit together nicely against the wall. Attach the new casing to the wall using screws or nails. You may also want to use construction adhesive for extra security. Finally, reinstall the door by slipping it into the opening and attaching the hinges.