How to turn off ringing trunks on phones on a SV9100

[mickyspring]

I have a SV9100 and the customer wants 8 CO trunks on some phones not to ring. I'm not seeing where i can turn off the ringing, i'm looking under "15-xx" - Extension set up but not seeing where or how to turn off the ringing.

 

[belevedere]

Try 22-04 incoming extension ring group.