Note: Service types that are configured on services are in use and cannot be deleted. In order to delete a service type in use, first determine which services are configured with the service type by checking the References tab and then edit those services to use another service type.
Select the service type you wish to delete in the service types panel on the left
Click the icon
Confirm that you wish to delete the service type on the pop-up window that appears
The service type is now removed and will no longer appear in the Service Types list.