If (a) the node is part of the cluster, and (b) is running and operational, then (c) the cluster will recognise that the node has a new IP when you restart the node and there's nothing to do on the C* side.
A new IP will be handled by C* automatically. Think of situations where a node experiences a hardware failure and you move the data disk to a new server which has a new IP. When you start C* on that node, it will be recognised as an existing node and that's normal. Cheers!
