While HostGator cannot modify nameservers at third party registrars on your behalf, we can provide you with instructions on how to do so. Here's how you can change your nameservers at Public Domain Registry (PDR).
PDR offers services to resellers, and does not allow non-reseller customers to register domains directly with them. If a WHOIS search indicates that PDR is the registrar, the domain itself is most likely registered through one of its many resellers.
Step 1: Find Out Nameservers for Your Hosting Account
The first step would be to find out which nameservers you should use for your HostGator hosting account. This varies by server and type of hosting. For instructions on how to find out your nameservers, please read the article:
Step 2: Changing Nameservers
You will need to visit the website or contact the reseller that you registered your domain with to change the nameservers. Since PDR offers resellers an API, reseller websites can vary dramatically, so it is hard to give specific instructions that would work across all PDR resellers.
Find the PDR Reseller for a Domain
If you do not know which PDR reseller you purchased the domain from, you can look it up on their website here:
Since HostGator is not affiliated with PDR or their resellers, you would need to contact PDR or the reseller for support if you need assistance with their website.