how to create an instance of a service?

I have a service:

(angular
 .module('app.services', ['ngResource'])
 .factory('MyService', [
     /******/ '$resource',
     function ($resource) {
         return $resource('myurl');
     }
 ])
);

I need to create an instance of it in my code. I know that angular can inject it if I list it as one of the parameters, but I am not asking about that. I need to create an instance of it "manually". How is it done?

EDIT:

this is related to my other question: a controller and its dependencies in a template

basically, I have a generic controller that takes a service as a parameter, and I need to create this controller manually using $controller object (to be able to use it in my template - please see the referenced question), and I need to supply a service object to it. My service needs an integer as a parameter, so I need to instantiate the service and set this integer on it as a property. Otherwise of course I would have just given the name of the service as a string to the $controller.