The battery is installed, RF antenna Kapton taped over the battery

You can put in a few screws, and connect it to the 24VAC doorbell to test, the doorbell button will light up blue after a few seconds (indicating that it's receiving power) and about 20-30 seconds after will turn green indicating that it's linked to your Lorex base unit. Press to test doorbell.

If all of that happens with fanfare and success, put in the rest of the screws and rubber feet, hook up the 2 doorbell wires permanently, place it about 1/2" raised and against the base mount, apply modest pressure and slide it downwards until it locks into place.