This post will explain to you how to change private nameserver and IP address in whm panel,

Step 1: WHM Login,

Login into your WHM Panel,

On Search box type the keyword "Basic cPanel & WHM Setup" and click on it

Step 2 : Update IP or Nameserver

Update Nameserver with that IP address,

page down to "Nameservers" place

Click on "Add an A Entry for this nameserver" and add ip address,

Update A Recrod and click on "Add Entry" and "close"

Step 3 : Assigned Nameserver IP's

Then, click on "Assign IP Address" for IP assigning to specific Nameserver

Finally click on "Save Changes"