How to Fix an Uneven Plaster Wall

Clear everything away from the uneven plaster wall and put a drop cloth on the floor. Put on goggles.

Strike a chisel against the uneven plaster wall with a hammer until it penetrates the wall.

Insert the blade of a reciprocating saw into the chiseled hole and cut out a square, a few inches larger than the uneven portion of the plaster wall.

Measure the square cut with a tape measure. Measure, mark and score a drywall sheet with a utility knife to create a patch the same size as the cut out square.

Insert the drywall patch into the square cut and fasten to the exposed wall studs with a screw gun and drywall screws.

Tape around the seams with drywall tape, then use a putty knife to spread joint compound over the entire patch. Allow the joint compound to dry for at least three hours, then sand smooth with sandpaper.

Apply a coat of primer to the patch, let dry, then paint over it with a matching paint using a paint roller to completely conceal the patch.