'Unassigns a registered instance from all of it\'s layers. The
instance remains in the stack as an unassigned instance and
can be assigned to another layer, as needed. You cannot use
this action with instances that were created with AWS
OpsWorks.
**Required Permissions**: To use this action, an IAM user must
have a Manage permissions level for the stack or an attached
policy that explicitly grants permissions. For more
information on user permissions, see `Managing User
Permissions`_.
:type instance_id: string
:param instance_id: The instance ID.'

def unassign_instance(self, instance_id):

    params = {'InstanceId': instance_id}
    return self.make_request(action='UnassignInstance', body=json.dumps(params))
