If the saprouter is going to be setup on a new server with a different IP then register that system (Hostname and IP) with SAP.
Set up the saprouter and configure saprouttab with or without SNC.
Refer this article Step by Step Procedure for SAP Router SNC Configuration
Adapt Tx OSS1 on all systems.
Modify the saprouter information in the System Data | SAP Support Portal with the new saprouter details for all the systems.
Stop the old saprouter and start the new saprouter.
Check the connectivity.
Cheers
RB