Gather drywall patch, utility knife, drywall saw, joint compound, putty knife, sandpaper, primer, and paint
Cut away loose drywall around the hole
Trim the hole into a neat square or rectangle
Cut a drywall patch to fit the opening
Secure the patch with drywall clips, backing strips, or a support piece if needed
Apply joint compound over the patch and tape seams if required
Let the compound dry completely
Apply additional thin coats of joint compound as needed
Sand the repaired area smooth
Wipe away dust
Apply primer
Paint to match the wall