If you have an existing domain name, you should change your name servers at your existing registrar - in this example, lets assume it's GoDaddy.
- Log into your GoDaddy Account Manager.
- Next to Domains, click the Manage button.
- Locate the domain you wish to register private name servers for and click the Gear icon, then select Manage DNS:
- In the Name Servers section of the Settings tab, click Manage.
- In the Name Server Settings pop-up, select the radio button for Custom, then click the Edit Name Servers link.
- Enter your name servers in the spaces provided, and click OK when you are done making changes.
- Click Save to finalize the changes.