OpenVZ VPSes pull the hostname from the config file which is updated when setting the hostname via our panel
Login to https://crownpanel.com/ and click on the "Manage" button beside the VPS you wish to edit the hostname for.
Next click on the "Hostname" listed beside the IP address,
This will open a new form where you can edit the hostname as you wish. Once the hostname is edited/changed, the VPS hostname is updated.