Peel the wallpaper edge away from the wall until you find the point where the wallpaper is still attached to the wall.
Wipe dried glue away from the wallpaper and wall with a damp cloth.
Apply the wallpaper border adhesive to the wall with a paintbrush. Press the wallpaper into the glue, smoothing it toward the seam so that no air remains under the wallpaper.
Roll over the repaired wallpaper with a wallpaper roller to smooth it out and press it into the adhesive. Wipe away any glue that leaked out with a damp cloth.
Cut out a piece of wallpaper that matches the pattern at the damaged spot with a utility knife, making it 1 inch larger than the damaged piece of wallpaper. The patch will extend over the original wallpaper seam, but if you match the pattern, the patch will not be obvious.
Apply wallpaper border adhesive to the back of the patch with a paintbrush. Let the glue dry until it becomes tacky.
Line up the patch over the damaged wallpaper and press it into place. Cut an irregular shape around the damaged wallpaper with a utility knife, cutting through the patch and the wallpaper. Gently peel away the patch, old wallpaper and excess patch.
Wipe the wall and wallpaper around the cut-out area with a damp cloth. Apply wallpaper border adhesive to the wall with a paintbrush.
Put the patch in place, lining up the wallpaper pattern. Press the patch with your fingers, removing air bubbles. Roll over the patch with a wallpaper roller and wipe away excess adhesive with a damp cloth.