How to Change the Primary IP Address of a WHM / cPanel server

On CentOS (v7.x) server running WHM cPanel (v58.0.19), the following steps are required to successfully change the primary IP address of the server.

In WHM:
Navigate to IP functions >> IP Migration Wizard
Enter the new IP address and complete all prompted steps

Via SSH:

nano /etc/sysconfig/network-scripts/ifcfg-eth0

then update IPADDR and GATEWAY to the new values, save and exit.

If GATEWAY information does not exist in this file, only then:

nano /etc/sysconfig/network

and update GATEWAY, save and exit.

nano /etc/ips

Replace the old primary IP with the new IP address, save and exit.

nano /var/cpanel/mainip

Replace the old primary IP with the new primary IP, save and exit.

nano /etc/hosts

Replace the old primary IP with the new primary IP, save and exit.

Restart the network, which will terminate your existing connection, command is:

service network restart

SSH back into server using new IP address and check network interface configuration (to ensure new address is in use), command is:

service network restart

In WHM:
Navigate to Server Configuration >> Basic cPanel & WHM Setup
Enter new IP address in appropriate field and save changes

In SSH:
Update the license key for cpanel, command is:

/usr/local/cpanel/cpkeyclt

If license is not properly updated, most likely solution is to log into cPanel (their service portal) and manually reassign the existing license to the new IP address; or contact their support.

Clean up:
DNS: Make sure to update A record, SPF(TXT), PTR (rDNS), etc. records
If the old IP address is no longer required, release it off the server
Wait for nameserver propagation to complete and test access to WHM URL.