To remove the cover and change the battery on your Emerson 1F83C-11PR Digital Thermostat, follow these steps: Remove the Thermostat from the Wall: Gently pull the thermostat straight off the wall plate. It should come off easily without the need for tools. Locate the Battery Compartment: On the back of the thermostat, you will see the battery compartment. Replace the Batteries: Remove the old batteries and insert two new AA alkaline batteries. Ensure the positive (+) and negative (-) ends are aligned correctly with the markings in the compartment. Reattach the Thermostat: Place the thermostat back onto the wall plate and press it firmly until it snaps into place.