In the event that one of your hostnames is no longer needed, you can easily delete it by following these steps:

1.  Log into your Dyn account. Screen Shot 2014-10-21 at 9.27.30 AM
2.  Click on My Hosts
3.  Select the hostname that you would like to remove from the DynDNS Hostnames list. ra_modify_hostnames
4.  Locate the link at the bottom of the Modify Hostname panel, and then click Delete. ra_delete_hostname
5.  Click OK to confirm this action. ra_delete_hostname_confirm