Log into your Hover account HERE.
If you have more than one domain name listed in your account, click on the domain name that you want to use with customized DNS records. This will take you to its Domain Details page.
Change Your Name Servers - Multiple Domains
To change name servers for multiple domains in your account, complete the following steps:
Hover over the Your Account menu, and select the option NAME SERVERS.
Put a check next to each domain name that you want to modify, then select Replace Nameservers from the drop down list and click on BULK EDIT.