To repair drywall, cut a piece of drywall that is large enough to cover the damaged area, remove the damaged drywall, and secure the patch to a board placed behind the hole in the drywall. Cover the patched area with joint compound, and sand and paint the patched area.
Before removing the damaged area, hold the new piece of drywall over the damaged area, and draw around the perimeter of the patch with a pencil. Mark the top of the patch with an identifying mark.
Use a utility knife to cut from each corner of the pencil outline to the center of the damaged area, and make a shallow cut along the edges of the outline. Press the drywall inward along the scored edge to loosen it, and use the utility knife to finish removing each piece.
Insert a piece of wood behind the hole that is 1 inch deep, 3 inches wide and 6 inches longer than the damaged area, and secure the wood to the wall with adhesive and screws. Set the patch into place, pressing gently to adhere the patch to the board, and apply joint compound over the patch, screw heads and seams. Allow the joint compound to dry completely before sanding and painting the patched area to match the existing wall.