1. Steps for WHM:
I. Log into WHM >> Basic cPanel & WHM Setup
II. Change the Primary IP here with the option that says "The IP address (only one address) that will be used for setting up shared IP virtual hosts"
Note: This might not actually be necessary.
2. Steps using SSH -
I. Login in to SSH.
II. Edit /etc/sysconfig/network-scripts/ifcfg-eth0
Change the IPADDR and GATEWAY lines to match the new IP and Gateway for the new ip.
III. Edit /etc/sysconfig/network
Change the GATEWAY line here if it does not exist in the ifcfg-* file.
IV.Edit /etc/ips
Change the GATEWAY line here if it does not exist in the ifcfg-* file.
IV.Edit /etc/ips
Remove the new primary IP from this file if it is present.
Add the old primary IP to this file with the format ::
Add the old primary IP to this file with the format ::
V. Edit /var/cpanel/mainip
Replace the old primary IP with the new primary IP.
VI. Edit /etc/hosts
Replace the old primary IP with the new one if needed. The hostname's dns will need to be updated too.
VII. Restart the network service to make the new IP the primary service network restart.
/etc/init.d/networking restart
Note: You will be disconnected from current SSH and will need to login new IP address
VIII. Restart the ipaliases script to bring up the additional IP.
service ipaliases restart
service ipaliases restart
IX. Run ifconfig and make sure all IPs show up correctly.
ifconfig
X. Update the cPanel license to the new primary IP. You will need to be in touch with the cPanel store from where you've ordred the cPanel license. Once done then fire below command -
/usr/local/cpanel/cpkeyclt
/usr/local/cpanel/cpkeyclt
XI. Verify you can still log in to WHM and there is no license warning.
XII. Verify cPanel
All done! 
