Click on the profile icon menu option then choose My Products.
Click the DNS button next to the domain you want to change the domain nameservers for.
Scroll down the dns page until you see the Nameservers section and click Change.
Choose Custom from the dropdown.
Enter your new nameservers in the text boxes. To add additional nameservers click the Add Nameserver button to the right of the textboxes.
Once all your nameservers are added click Save.
Once your nameservers have been added and saved you should see something similar to the following (with your own nameservers showing):
That’s all there is to it! Now you just need to wait for the changes to take affect which can be anywhere from a few minutes to 48 hours. In my experience it’s usually somewhere between a few minutes and a few hours so keep checking back. Sometimes your browser will keep showing you the old page even though the dns has updated because of caching so either clear your cache or check from a different browser or device.