Hello JDT,
It is relatively easy to setup. You probably also have to setup ypur NAS device to make it point to the machine that runs SEP using the ICAP protocol.
I did a paper of this for out Oracle ZFS Storage Appliance, it describes SAV but I did test SEP 7.0 last week, works exactly the same. See paper
http://www.oracle.com/technetwork/server-storage/sun-unified-storage/documentation/symantec-antivirus-050112-1636111.pdf
I'm in the process of updating the screenshots to reflect SEP 7.0 install
Peter