Turn off power to the bathroom fan at the breaker
Verify the power is off with a voltage tester
Remove the fan grille
Remove the fan housing cover if present
Disconnect the wiring
Unscrew the fan housing from the ceiling joists or mounting bracket
Detach the duct from the old fan
Remove the old fan assembly
Compare the new fan to the old opening
Enlarge or adjust the opening if needed
Attach the new fan housing to the joists or bracket
Reconnect the duct to the new fan
Connect the wiring according to the manufacturer’s instructions
Secure all wire connections with wire nuts
Install the fan motor and blower assembly
Attach the grille
Restore power at the breaker
Test the fan for proper operation
Check for airflow and unusual noise
Seal gaps around the housing if needed