Scrape off as much of the peeling paint as possible by using a wire brush.
Add 1 part ammonia to 3 parts water in a bowl.
Moisten a cloth with the ammonia solution and wipe down the wall to remove any oil, grease or dirt.
Wipe down the wall with a sponge moistened with water to remove the ammonia solution.
Sand the edges of the remaining peeling paint with sandpaper to create a smooth surface.
Apply a paint sealer to the surface working into the cracks of the old paint. Paint sealers can be purchased at most hardware stores.
Apply a paint primer to the wall after the sealer has dried. This may take up to eight hours to thoroughly dry. It is best to allow the paint to dry overnight to ensure it is completely dry.
Repaint the area where paint has peeled after the primer has dried. Wait at least eight hours to paint the second coat. You may also touch the paint in an inconspicuous area to ensure the paint is dry. If it still feels sticky to the touch, allow the paint to dry for an additional two hours and then spot test again for dryness.