Prepare a cleaning solution by mixing 1/4 cup of mild soap with 1 gallon of warm water.
Apply cleaning solution with a cloth or spray bottle and allow it to penetrate the soiled area on the Sunbrella fabric. Rub with sponge, cloth or soft brush to clean.
Rinse with plenty of clean water.
Allow fabric to air dry.
Iron away wrinkles if needed on the "synthetic" setting (100 degrees F) on your iron. Higher heat will melt the Sunbrella fabric.
Treat the fabric with protectant to restore its water repellent finish. Sunbrella recommends 303 High Tech Fabric Guard . Follow the directions on the package.