The great news when it comes to removing paint from resin furniture is that most kinds of paint will eventually come off dyes, making it easier to remove it from your resin seats than it is to remove it from your wood seats. The bad news is resin doesn’t do well with very harsh solvents like paint thinners, therefore it could take more elbow grease than burning wood. Don’t be concerned about scrubbing hard with an abrasive — the surface can help the new coat of paint stick.
Rub a generous coating of pine cleaner over the colored resin and let it sit for about ten minutes.
Mix one piece pine cleaner and one part water in a bottle.
Scrub the paint away from the treated resin chair with steel wool, then spraying diluted cleaner onto the surface as necessary to keep it moist as you scrub.
Use a little bit of paint thinner on a cloth on areas where the paint is hard to remove.
Rinse the chair and permit it to dry.
Sand the entire surface of the chair with a rotary tool fitted with a sanding disc accessory to prepare for painting and remove any residual paint.