I recently got Season 1 of Pawn Stars and going through it I was wondering how to do the cast for the main guys.

During the opening there is no text credits, but Rick says "I'm Rick Harrison and this is my Pawn Shop. I work here with my old man, and my son Big Hoss......"

Going through several of the episodes and during the show they are credited with just a single name, such as Chumlee or Corey and Old Man.
All that's credited in the end credits is the crew.

So a couple of questions.
1. How are they actually credited in the other seasons and/or dvd compilations?
2. What is the proper way to credit them?