Wear gloves, goggles, and an N95 or better respirator
Ventilate the area by opening windows and using fans that exhaust outdoors
Fix the moisture source first
Remove and discard porous materials that are heavily mold-infested, such as drywall, carpet, insulation, and ceiling tiles
Clean non-porous surfaces with soap and water first
Apply a mold-killing cleaner such as diluted bleach, hydrogen peroxide, or a commercial mold remover, following the product label
Scrub the surface thoroughly
Let the cleaner sit for the recommended contact time
Rinse and dry the area completely
Use a dehumidifier to keep indoor humidity below 50%
Replace damaged materials only after the area is fully dry
Dispose of contaminated waste in sealed bags
Call a professional remediation service for large infestations or HVAC contamination