How to Replace a Bathroom Ceiling Fan

Turn off all power to the bathroom, at the house circuit box. Set your ladder under the existing vent, climb it and use your screwdriver to remove the vent cover.

Go into the attic and locate the existing unit, which will be a metal box on the attic floor. Unscrew the mounting screws or bolts holding it to the ceiling joists.

Disconnect the wiring wherever there are wire nuts between the box and the house wiring. (Note: The connections may be inside the box, which will mean removing a cover from the box to get to them.) Remove the box, leaving a square hole that looks down into the room below.

Set your new exhaust fan on the attic floor, with the intake vent facing down over the hole left by the previous fan. If the new fixture is larger than the old one, trace around the perimeter of the vent with a pencil, remove the unit and cut around the line with your jigsaw.

Set the new unit back in place so the intake vent drops down through the hole. Mount it to the joists on either side, using the provided screws and securing them with your screw gun.

Attach the new unit to the old exhaust hose, which should run to a nearby external wall. Seal the connection between the new unit and the old exhaust hose with duct tape.

Wire the new unit to the house wires that you disconnected earlier, connecting them with the same color wires (white to white, black to black), using wire nuts and wrapping the connections in electrician's tape. Wrap the bare copper grounding wire from the house around the green grounding screw on the new unit. Tuck the connections into the electrical box of the new unit and secure the cover over it, following the instructions on the packaging of the unit.

Go back down into the bathroom. Climb the ladder, and install the new vent cover over the opening according to the instructions (it will screw in, or attach with hooks and springs). Turn on the power.