I take it you're talking about filework on the blade. Bill posted a bunch of pics of Josh's razor along with descriptions when the razor was being made. It's slipped my mind what, if any process he used to layout a pattern though.

The thing is, that adding some sort of filing/worked back to a razor is usually done before the razor is heat treated. This way, the steel is soft and can much more easily be filed off. I'm sure there's a way to do it on a finished razor, but I don't think standard files would cut it.