I do not work for vmware - however as i understand the best way to do this (please verify with support or your rep) is shutdown cloud - then take a backup of the vShieldmanager (feature in vSM to do this, not a snapshot) - shutdown the VSM - install a NEW vSM with the IP and settings of the old one. Then RESTORE the backup. At this point get cloud back up and you are on you way.
Again, might want to double check these steps, but I know even for the 5.0 -> 5.1.2 upgrade you are suppose to do a clean install like this after the upgrade is done as a clean server has functions/fixes that upgrades ones may not. (KB article on the upgrade process covers this)