How does WCF help giving access to outside clients?

I studied the Design Pattern Framework and I finally get the whole application finally.

My question now is how does having a WCF service help in this example if outside clients need to access it? I couldn't imagine giving a url to expose the methods if I have to tell them to add an AuthRepository Class, RepositoryBase class, and a RequestHelper class. Am I missing something but if someone outside needs to access my service how is having all these classes needed beneficial? Is there a way around this? I'm probably not understanding something here but a lot of work is needed in my opinion and I don't see how you explain to a client/user all the work/coding needed to access the service.

Thanks
Dennis