Slide your cured screen printed item over the vacuum surface of your extraction system. The extraction system is a high powered vacuum system that pulls the plastisol remover, plastisol and vapors away from you. You only want the screen printed portion of the item over the actual vacuum surface; similar to the way you would slide an item over the end of an ironing board to iron one side of it.
Put on your gloves and eye protection. Plastisol removers can be made from hazardous chemicals that you do not want on your skin or in your eyes. You can also wear an apron to prevent getting it on the clothes you are wearing.
Turn on the extraction system and fill the bottle on your spot cleaner gun with plastisol remover. You can find extraction systems, spot cleaning guns and plastisol remover at many screen printing supply companies (see Resources).
Point the nozzle of your spot remover gun at the cured screen printing you want to remove. Make sure your gun is on. Pull the trigger and spray the entire area of printing you want to remove. You may need to stop and move the printed article to get all of the screen printing you need to remove; do not shut off your extraction system at this time, though.
Allow your extraction system to pull away any cleaner and any screen printing ink that it can. Then turn off the extraction system.
Wash and dry the article normally, according to care instructions for the fabric type.