Take the fabric outside and brush off loose mildew
Wear gloves and a mask
Check the care label before cleaning
Wash the fabric in the hottest water safe for the material
Add laundry detergent and a mildew remover or oxygen bleach if safe
Soak the fabric in a solution of water and white vinegar or oxygen bleach if needed
Scrub stained areas gently with a soft brush
Rinse thoroughly
Wash again if the smell or stains remain
Dry the fabric completely in direct sunlight if possible
Repeat the treatment if mildew persists
Do not put the fabric away until it is fully dry
Store clean fabric in a cool, dry, well-ventilated place