Log in as the user or group under which Calendar Server is running (such as icsuser and icsgroup) that was specified during installation, or as root
If you want this attribute change to be recognized immediately, stop Calendar Server. Otherwise, you do not have to stop Calendar Server.
Change to the sbin directory.
Use the csattribute delete command to delete an attribute from a user or a resource. For example, to delete the LDAP attribute icsCalendar with the value Conference_Schedule from the user tchang:
./csattribute -a icsCalendar=Conference_Schedule -t user -d sesta.com delete tchang