To modify the properties of a calendar, use the cscal utility modify command.
For example, to change the group scheduling access control settings of AllAdmins and specify RJones@sesta.com as another owner:
cscal -a "@@o^c^wd^g" -y RJones@sesta.com modify AllAdmins
The following explains the two command variables used in the preceding example:
-a "@@o^c^wd^g" grants owners write and delete access to the components (events and tasks) of AllAdmins.
-y RJones@sesta.com specifies the user ID of the other owner.