Under Centralized Programming for each extension is how it's done.
From the top"
System Program> START > More > Cntr-Pgr > Program Ext >
ENTER THE EXTENSION NUMBER - 11 As an example -
Touch ANY LINE BUTTON and press *346.
That will set ALL LINES to delay ring on that extension.
THEN, Press SYS PROGRAM, and then BACK and do COPY EXT from the one you just did to all the others you want.
That should take care of it....