Unscrew the shutters with either a Phillips or a flat-head screwdriver. Lay the screws in a safe area to keep from losing them. Remove all the exterior shutters from the house.
Fill a bucket with warm water and 2 teaspoons of an acid-based detergent. Wash the shutters with the soapy water and a rag. Rinse the shutters with a garden hose or buckets of water, and dry them with old towels.
Sand the shutters lightly with a 120-grit sandpaper. Wipe any residue from the shutters with a lint-free cloth.
Lay old sheets on a concrete patio or on the ground. Place newspapers on top of the sheets. Lay a shutter on the newspaper. Apply one coat of latex primer with a medium-width paint brush. Allow the primer to dry for two hours.
Paint the shutters with an exterior latex paint using the same paint brush. Use a smaller brush to paint into any small crevices in the shutters. Allow the paint to dry for two to three hours before placing back on the house.
Position the shutters on the house. Screw into place with the screwdriver.