Rinse the door with a hose to remove superficial dirt and debris.
Remove the door from its hinges using a screwdriver. Lay the door flat on a drop cloth.
Remove the door handle by removing the two screws on the base around the handle. If you don't want to remove the handle, you can cover it with a plastic bag using painter's tape or masking tape to secure the bag and to cover any exposed areas of metal.
Place a few drops of dish soap in a bucket, fill the bucket with warm water and sponge the soapy water onto the door. The dish soap will remove dirt and will break up oils that are present on the door.
Scrub the door with a scrub brush, using a circular motion to remove dirt and grime. Most vinyl doors have a faux wood texture, so scrubbing is required to remove dirt from these indentations.
Rinse the door with a hose and allow the door to air dry before proceeding.
Don a face mask or respirator to avoid inhaling primer and paint fumes.
Place a liner inside the paint tray, stir the primer-bonder and pour some into the tray, enough to cover the bottom of the reservoir situated at the lower end of the tray.
Apply an even coat of primer-bonder to the door's surface. Allow the door to dry before proceeding. The recommended drying time varies among products, so read the label to determine how long you need to wait before painting.
Pour remaining primer-bonder into the canister and dispose of the tray liner and roller. Replace with a new paint roller and a new paint tray liner.
Stir the paint before pouring it into the tray.
Paint the door, applying a thin, even coat. If a second coat is recommended (read the product label), allow the first coat to dry first.
Place the door back on its hinges, and replace the door handle once the paint has dried. Avoid using the door until the paint has set. Setting usually takes 36 to 72 hours. Read the product label to determine the setting time.