More in Windows Walls and Doors
Cut out a rectangular patch that's a few inches bigger than the damaged area. You can use a piece of wall covering that was left over from when the covering was initially installed. If you don't have a piece, look for a place where you can "steal" a patch -- such as behind the refrigerator, inside a closet or behind a mirror.
Determine how the original paper was applied. If it was pre-pasted on the back, you'll need to dampen the back of the patch with a sponge to activate the adhesive; otherwise, coat the back of the patch with a thin layer of wallpaper paste.
Making certain that your patch lines up precisely with the pattern on the installed wall covering (Image 1), press the patch firmly into place (Image 2) and wait for three to five minutes for the paste to set.
Once the paste has had a chance to set up, use a utility knife with a new blade and a straightedge to cut a rectangle around the inside of the patched area (Image 1). Cut straight lines to form a neat cutout and avoid overcutting the corners. Once you've made your cuts, remove the portion of excess wallcovering surrounding the newly-cut area.
Then, very carefully pull off the newly-made patch from the middle (Image 2).
Use the utility knife to pull up the newly cut corners of the damaged piece that was underneath the patch, and carefully pull up and remove the damaged section.