How to Retrofit Smoke Detectors

Trip the circuit breaker at the fuse box that supplies power to the room or area in which the smoke detector that will be removed is located.

Place a ladder so that you can reach the existing smoke detector. Typically, the detector will be on the wall just below the ceiling, although in some cases it can be installed in the ceiling itself.

Remove the screws surrounding the smoke detector with a Phillips screwdriver. Pull the smoke detector off the ceiling. Remove the screw-tab connectors that are wound around the twisted pairs of wires; use a counterclockwise motion to remove the connectors from the wires.

Pull the wires apart from each other. Dispose of the smoke detector according to the hazardous waste guidelines for your area.

Pull the wiring that is in the hole or in the wall though the center of the smoke detector's base plate. Place the plate over the hole, onto the wall or ceiling. Screw wood screws through the holes in the plate and into the ceiling or wall using a Phillips screwdriver.

Pull the top off the smoke detector. If the top doesn't pull off, twist the top counterclockwise to remove it instead. Place a compatible backup battery into the battery compartment inside the detector. Return the top to the detector.

Strip a 1/2 inch of insulation off the ends of the three wires attached to the back of the smoke detector. If a wired tab insert is used instead, insert the tab into the corresponding slot on the bottom of the detector and ignore cutting the wires, as they are already pre-stripped.

Wind the end of the black wire from the detector around the end of the black wire coming out of the hole. Wind the end of the white wire from the detector around the end of the white wire coming out of the hole. Screw a screw-tab connector clockwise over each pair of twisted wires.

Loosen the screw at one of the bottom corners of the electrical junction box that is inside the hole with the Phillips screwdriver. Wind the end of the final wire (copper-colored or bare) from the detector around the screw. Tighten the screw.

Place the bottom of the smoke detector against the base plate. Twist the detector clockwise to seat it on the base. Place the ladder away and restore the electric power at the fuse box.