How do I physically install the alarm on the wall?

First, position the mounting plate on the wall, mark the holes with a pencil, and drill two holes (6mm diameter, 40mm deep). Insert the two plastic anchors and screw the mounting plate securely to the wall. Once confirmed secure, power on the alarm, run a test, and if the result is normal, slide the alarm down over the mounting plate until it snaps into place — note that it cannot snap into place until batteries are correctly installed.