Press [Administrator Tools] on the [System Settings] screen.
For details about how to access the [System Settings] screen, see Displaying the Printer Configuration Screens Using the Control Panel.
Press [] to display [Program/Change/Delete Realm].
Press [Program/Change/Delete Realm].
Press [Delete].
Select the realm you want to delete.
Press [Yes].
Press [Exit].
Press the [User Tools] key.