It's an all or nothing command that's broadcast out to all agents that are connected.
You'll need to connect to the appliance console, then do 'manager' then 'rcc', it'll launch a little mini-shell, then there's a third command you'll have to run from there, which is 'changeManagerHostname' with the new hostname/IP.
I'd recommend running through this sequence on a backup/test appliance since it's relatively destructive.