Circuit Cut Overs can be Easy or Complicated

The Internet Service Provider (ISP) will install a new Internet Circuit with a new Modem, and Usually use Coax splitters to get everything up and Running

The Basic Concept is to Move the Ethernet cable from the Old ISP Modem, to the New ISP Modem.

This will give the site a new Internet circuit for their Business

Follow the Remote Support Guidance to complete this Smoothly. 

Be sure to run a speedtest on the New Internet Circuit to make sure the Internet speeds are where they need to be.