To replace the call button batteries, follow the steps below;

  1. Remove the name cover. (under the call button)
  2. You will now see a rubber tip, remove it.
  3. Then screw out the little screw. 
  4. Using a screwdriver, pry open the bell via the underside.
  5. Replace the CR-2032 battery.
  6. Click the bell closed again.

The doorbell is ready to use again.