Log in to WebHost Manager using root for your username and your server's password at https://yourserverip:2087, where yourserverip is your server's IP address.
Click DNS Functions.
Click Edit DNS Zone.
Select the domain name you want to use, and then click Edit.
For the two rows with the menu displaying NS, edit the right-most columns to ns1.your domain name. and ns2.your domain name., respectively.
You have to enter a "." after your nameserver for the DNS to work properly.
In the Add New Entries Below this Line section, do the following in the first row:
First field: Type ns1.
Second field: Type 14400.
Third field: Select A.
Fourth field: Enter your server's IP address.
Then, in the second row, do the following:
First field: Type ns2.
Second field: Type 14400.
Third field: Select A.
Fourth field: Enter your server's IP address.
Click Save.