Take the leather item outside
Wear gloves and a mask
Brush off loose mold with a soft brush
Wipe the surface with a dry microfiber cloth
Mix equal parts white vinegar and water
Dampen a cloth with the solution
Test on a hidden area first
Gently wipe the moldy areas
Use a clean dry cloth to remove moisture
Let the leather air-dry completely
Keep it away from direct heat and sunlight
Apply a leather conditioner after drying
Repeat if needed
Store leather in a cool, dry place