'Removes existing hard disk
:param server_id: Id of the server
:rtype: ``str``
:param hdd_id: Id of the hard disk
:rtype: ``str``
:return:    Instance of class ``Node``
:rtype:     :class: `Node`'

def ex_remove_hdd(self, server_id, hdd_id):

    response = self.connection.request(action=('servers/%s/hardware/hdds/%s' % (server_id, hdd_id)), method='DELETE')
    return self._to_node(response.object)
