Command 55. The command center will prompt for the code to be changed. Key in code to be changed and the enter key. The command center will prompt for the new code. Key in the new code and enter, the keypad will prompt for the new code again. Key in the new code and enter a second time. The code has to be between 3 and 6 digits long, and must be seperated from any existing code by at least 3 digits. For example, if you have a code of 1234, you cannot have a code of 1232 or 1233, 1235 or 1236.