xna 4.0 - Resolution Independent 2D Rendering in XNA

I am trying to figure out the best way to render a 2d game at any resolution.

I am currently rendering the game at 1920x1200. I am trying scale the game to any user selected resolution without changing the way I am rendering, or game logic.

What is the best way to scale a game to any arbitrary resolution?

Edit: I am trying to achieve this:

http://www.david-amador.com/2010/03/xna-2d-independent-resolution-rendering/

but I think the code he has is for a different version of XNA because I cannot find that method overload he uses.