Minor wallpaper problems like blisters or peeling are fairly easy to fix. A blister is caused when air is trapped beneath the paper. First, try pricking it with a pin and squeezing out the excess air. If that doesn't work, cut an X in the paper with the blister in the center. Carefully peel back the four flaps. If there's excess adhesive on the wall beneath, scrape it off. Apply adhesive to the flaps and carefully press them back in place. Use a seam roller especially made for wall coverings to smooth the area. If your wallpaper is peeling at a seam, pull it slightly away from the wall and use an artist's brush to apply adhesive to the back. Use a roller to flatten the seam and stick a few pins into it to hold it in place while the adhesive dries. If you need to patch an area of wallpaper, cut out a section of paper to use as a patch and use masking tape to attach it to the wall over the damaged area. Next, use a utility knife to cut around the section you want to patch, cutting through both the patch and the paper under it. Remove the taped patch paper and save the section you cut out. Now scrape away the old wallpaper and remove any old adhesive. If there's a ding in the wallboard, fill it with joint compound and let it dry. Finally, glue the patch in place and flatten it. It should fit the hole perfectly.
