How to Change a Door Header

Lay a drop cloth under the door to cover the entire doorway area. You can replace a door header without removing the door from its hinges if desired, but the work will inevitably dirty your floor or carpet if you don't take the necessary precautions. Leave the door wide open if you choose not to uninstall it for the duration of the repair.

Saw through and remove the drywall just above the door to reveal the existing door header. Remove a piece of plaster wide enough to completely reveal the header and cripple studs, as well as the top portion of the jack and king studs.

Remove all screws and pull out all nails that connect the existing header to the surrounding studs. Slide the header out and use a hammer or mallet to knock it loose if necessary. Wedge a vertical 2-by-4 into the opening to support the doorway.

Measure the width of the old header. Cut two 2-by-4s to this length. Trim a piece of 1/2-inch lumber to the vertical and horizontal dimensions of the 2-by-4s and sandwich it between them then screw all three pieces together.

Remove the temporary support beam and slide the new header into place. If necessary, use the hammer again to knock it into position. Diagonally screw, or "toe-nail," the header to all the surrounding studs. Install a new interior drywall section to cover the header.