Pull out all rusted and/or corroded nails, using a claw hammer. Put the old nails in a bucket to prevent them from being stepped on later. Hammer in new nails.
Spray the picket fence with a garden hose or pressure washer. Fill a bucket with soap and water. Clean the picket fence thoroughly to get off any grime and dirt. Don't be worried about chipping or flaking paint.
Put on gloves, safety glasses and a dust mask. Remove the old paint with a combination of paint remover, a putty knife and sandpaper. Rinse thoroughly with a garden hose or pressure washer once again. Let the fence air-dry.
Apply primer to each picket or plank, using a paintbrush. Let the paint dry for two to three hours, or as long as suggested by the manufacturer. Next, apply the first coat of exterior white paint and let it dry. Apply a second coat.
Purchase new hinges and latch hardware. Unfasten the old hinges and latch with a screwdriver or screw gun. Install the new hardware on the fence. Your white picket fence will now look good as new.