1. May refer to this link in order to log into the Exabytes Billing System.
2. Click on 'Domains' >> 'My Domains' as per screen shot below: 
3. Select the domain name that needs the modifications, click on the vertical 3 dots (...) next to the domain status and click the 'Manage Nameservers'.
4. Select the second option: 'Use custom nameservers (enter below) and enter your preferred sets of name servers.
5. Click on 'Change Nameservers' once done.
You may contact us at domain@exabytes.sg should you need further assistance.
Notes: By proceeding, you agree to the Mynic Policy & Procedure.