Turn off power to the fan at the breaker
Remove the fan cover
Wash the cover with warm water and mild soap
Dry the cover completely
Vacuum dust from the fan housing and blades
Use a soft brush or microfiber cloth to remove stuck-on dust
Wipe the blades and housing with a damp cloth
Avoid getting water into the motor
Clean the vent duct opening if accessible
Check for mold or heavy buildup and clean carefully
Reinstall the cover
Restore power and test the fan