encapsulating webservice proxy to hide complexity

I'm to deploy a .NET DLL which internally communicates with the WS. I
don't want others to see internal complexity of the web service
classes generated by "Add a Web reference" VS option.
As a WebSerive contains a lot of methods and different types creating
a web proxy class manually is too time consuming.

I tried to edit a class manually, changing the highest-level access
modifiers from public to internal - this way I could use the classes
from within the DLL, exposing only my API. However, this does not work
correctly - "some" of the classes have to be public (e.g. a class
defined as a SoapHeader, but not only) - when changing the access
modifier to internal, I got an error "Method XXX can not be reflected"
when trying to create an instance of the web proxy...

So the question is:
a) where could I find some information what is exactly done by
hte .NET framework during a proxy class lifetime
b) is there any other method (preferably automatic...) to hide as much
information as possible from the proxy class?
Thanks

.