Sand any areas of the mural that contain texture. Use a palm sander to sand a large area with ease and speed. Wipe any dust off the wall with a tack cloth.
Place a strip of tape around the wall that contains the mural. Be sure to use a low-tack masking tape to avoid pulling off any wall paint.
Roll a coat of primer over the old mural. Paint the primer in along the edges with a brush.
Plan a new mural. Work from a photograph or design your own scene. You can use painter's tape to create an abstract arrangement of shapes or intersecting lines.
Mark out your new mural on the wall with chalk. Use a strip of tape to keep painted edges sharp, if desired.
Mix water-based paints on plastic plates. Do not mix all your colors at once, as acrylics and other water-based paints do not stay workable for very long.
Apply the paint with a small foam roller or a paintbrush. Use a foam roller to add large areas of a single color or paint inside a taped shape. Use brushes of various sizes to paint details. Paint the background first and add details last.