Scrape off each individual blister with a 5-in-1 putty knife. Hold the tool with its blade flat against the work surface and its handle at a 30-degree angle to the surface.
Smooth each spot with sanding screens. Fold each screen in half and scrub the area until it erases the the blemish completely.
Apply a dab of paint to each spot with your paintbrush. Lightly brush the tips of the bristles back and forth against each spot to thin the paint and blend it into the surrounding paint.
Paint the borders of the entire work surface with your brush. Paint around the entire wall to begin a whole new coat of paint, insuring uniform coverage over the entire surface.
Slide a roller screen into your bucket of paint. Dip your roller into the paint and roll it on the screen to obtain an even coat of paint on the entire cylinder. Paint the inside of the new borders of the surface with your roller.
Remove all the paint with sanding screens. Scrub the entire work surface, removing all the paint, leaving the bare drywall exposed.
Inspect the surface of the wall for damage. Remove any damaged drywall with your razor knife and screw gun. Attach new drywall boards with drywall screws and a screw gun.
Apply a thin coat of drywall compound over any screw head with a 6-inch drywall knife and every seam with a 12-inch drywall knife. Press a piece of drywall tape into the compound covering every seam. Smooth the tape by dragging the blade of your 12-inch knife along its entire length.
Repair any smaller damaged spots, such as nicks, dings or cuts in the surface, filling each one with compound. Apply the compound with a 12-inch knife. Smooth each repair spot by pulling your 12-inch knife in an arc across its surface. Let the compound dry completely before smoothing the wall with sanding screens.
Paint the borders with a brush. Paint the remaining surface with a roller. Let the paint dry for one hour. Apply a second coat of paint to the entire surface. Let it dry for one hour. Inspect the finished wall and touch up as needed.