code: def remove_user_from_group(self, group_name, user_name):
          
          params = {'GroupName' : group_name,
                    'UserName' : user_name}
          return self.get_response('RemoveUserFromGroup', params)
docs: Remove a user from a group.
  
          :type group_name: string
          :param group_name: The name of the group
  
          :type user_name: string
          :param user_name: The user to remove from the group.