Clean the garage door thoroughly with soap and water
Rinse and let the door dry completely
Remove dirt, grease, mildew, and loose paint
Sand the surface lightly to smooth rough areas
Scrape off any peeling paint
Repair dents, holes, or cracks with filler
Remove or tape off hardware, handles, and trim
Cover nearby surfaces with drop cloths or plastic sheeting
Apply a primer if the door is bare metal, bare wood, or heavily patched
Stir the paint well before use
Use exterior paint suitable for the door material
Paint from top to bottom
Use a brush for edges and a roller or sprayer for flat panels
Apply thin, even coats
Let the first coat dry completely
Apply a second coat if needed
Check for missed spots and touch them up
Remove tape before the paint fully hardens
Reinstall hardware after the paint cures
Keep the door open or partially open while drying if needed