How do I add or delete user security codes on the VISTA-20P?

To add a user, enter the System or Partition Master code + [8] + the user number + the new user's 4-digit security code; the keypad beeps once to confirm. To delete a user, enter the System or Partition Master code + [8] + the user number + [#] [0], which erases the security code and all attributes for that user number. The VISTA-20P supports up to 47 additional user codes beyond the master code. (Page 33)