You can usually find all the components you need in one kit. The first step is to remove the old alarm, if there is one, and disconnect the wiring. Next, drill holes in the walls for mounting the control panel and sensors. Run the wiring from each sensor to the control panel, being careful not to damage it. Mount or stick up the control panel and test that everything is working properly. Finally, reattach the siren (if there is one) and hide all of the wires.

1. Decide on the type of alarm you want. There are three common types of alarms- monitored, self monitored, and unmonitored. Monitored alarms are connected to a security company who will contact the police if an intruder is detected. Self-monitored alarms allow you to contact the police directly in case of an emergency. Unmonitored alarms do not have these features and are cheaper. 2. Choose a location for the alarm panel. The panel should be located near an electrical outlet and should be easily accessible in case of an emergency. 3. Run the wiring according to the manufacturer's instructions. Be sure to follow local building codes when running wires through walls.