Disconnect the AC power cable and battery from the alarm panel. There should be no power reaching the alarm.
Pull the wires out of the Zone 1 and PGM terminals.
Connect the Zone 1 and PGM terminals together with a short piece of wire for a few seconds.
Reconnect the AC power supply to the alarm panel and wait for the Zone 1 light to glow.
Disconnect the AC power and replace the battery. Reconnect the wires to the Zone 1 and PGM 1 terminals and plug the alarm panel back in. The system default is complete.
Touch the "asterisk" button then "8" on the front of the alarm panel. The system will enter Installer Programming mode.
Press the "9" button three times and enter the system's installer code. The default installer code is "5010," but you may have changed it when the system was installed.
Press "9" three more times to confirm the default. The system will take a few seconds to return to the factory settings.