Hostgator dedicated server self-signed certificates

The self-signed certificates on a Hostgator dedicated server were nearing expiry, and notification emails like 'The SSL certificate for xxx on yyy.com will expire in less than 30 days' were starting to appear.

After going through domain verification on chat, found that they don't do SSL install support on live support.

Then, followed the WHM link given in the notification email sent by cPanel,
You need to install a new certificate as soon as possible. You can do this with WHM's Manage Service SSL Certificates interface at
https://yyy.com:2087/scripts2/manageservicecrts.

There was a button for 'Reset certificate' - just clicked that, and the self signed certificate was renewed for a year.