Do your programming from the Console phone:
Menu, SysProgram, Start (or Exit if it is a Legend)
If the lines are not already assigned to the extensions:
Go to Extensions, Lines and Trunks, dial the Extension Number, press Enter. Press Entry Mode, dial the Line Number that you want to assign to the extension, press Enter.
Once the lines are assigned to the extensions:
Press Centralized Telephone Programming, Program Extension, dial the Extension Number and Enter. Press the line button (confirm on the display that you have pressed the correct button), then dial
*35 for NO ring
*36 for DELAYED ring
*37 for IMMEDIATE ring