Remove the couch cushions from the couch. Unzip the back of the cushions and pull out the old batting.
Turn cushion covers inside out and wash them on gentle cycle in cold water. Allow them to dry.
Cut batting to the appropriate size for your cushions. The best tool for cutting batting is a shrub trimmer. It is large enough and leaves a clean cut. If you do not have one, you can use a razor blade.
Turn the covers right side out. Lay flat on the floor; begin in the right corner placing the batting in the cushion. When the batting is fully in, zip up the cushion and place on the couch. Repeat process with other cushions.