How to replace battery on smoke alarm

Remove the alarm by rotating it counter clockwise in the mount.

The alarm should fall off once rotated enough. The cable should be the only thing holding it in place if done correctly.

Unplug the cable from the alarm.

Press down on the catch on the top left of the alarm to open the battery compartment.

Remove the battery and dispose of it properly.

Replace the old battery with a new 9V battery and close the compartment.

You should hear a click to know that the compartment is secured.

Line up the holes of the cable on the mount with the pins on the alarm.

Reconnect the cable on the mount to that on the alarm.

It should insert itself with minimal force.

Press the alarm into the mount.

Rotate the alarm clockwise until it does not turn anymore. This makes sure the alarm is secured.