Rub medium-grain sandpaper over the damaged area to remove roughness and torn edges from the wall. Use small, circular motions with the sandpaper.
Rub fine-grain sandpaper over the area to smooth down the texture of the damaged area to be flush with the wall. Use small, circular motions, as before.
Wipe off the wall using a towel to remove any dust.
Coat a putty knife with a thick dob of drywall joint compound, and press the joint compound against the holes or cracks on the damaged area of drywall. Gently work the compound into the dents, holes and cracks until they are filled with the compound.
Scrape the drywall joint compound flush with the rest of the wall by running the flat edge of the putty knife down the patched area. This will remove the excess material and will cause the area to look as though it never had holes or cracks. Repeat this process over all of the damaged areas. Allow the patched areas to dry completely before you paint or finish the drywall.