Add, Delete, and Change Vista 20P user codes - includes removing key fobs

To change master code:

Installer code + 8 + 02 + new code

To add a new user:

Master Code + 8 + user slot + new code

To delete user code:

Master Code + 8 + user slot + # 0

Removing Key Fobs:  
Press *56 while in programming mode then enter one of the wireless zones used by the fob you wish to remove. Scroll through the prompt by pressing * until the S/N prompt appears. Enter 0 for the loop number and press *.  
Exit programming mode.