To change the Master manager code go to the main alarm panel with the LCD screen (like the above image):
Press D followed by your user code.
Keep pressing “No” until you see “Edit Users” and then Press “Yes”
Keep Pressing “No” until you see “Change Master Manager Code” then press “Yes”
Now Press “C” to clear the code and enter your new code followed by “Yes” twice
Now keep pressing “No” until you see “Exit Manager Menu” then press “Yes”
Your Burglar Alarm code has now been changed.