1) Push in the push tabs located on the panel's top side and open the back panel
2) Next to the back up battery is where the communicator lives in the panel
- here you should see Mac and CRC located on the communicator
https://www.youtube.com/watch?v=icxIsyF7Iho&list=PLGdtWAgjdwqGv_tUrH23U5VOJWJagU9qz&index=33