Wear gloves, goggles, and a mask
Open windows and run the bathroom fan
Mix 1 part bleach with 3 parts water, or use white vinegar
Test the solution on a small hidden area first
Spray the moldy ceiling lightly
Let it sit for 10 to 15 minutes
Scrub gently with a sponge or soft brush
Wipe the area with a clean damp cloth
Repeat if needed
Dry the ceiling completely
Fix the moisture source to prevent mold from returning