Artist and game designer Ramsey Nasser appropriated id Software’s open-source Wolfenstein (1992) assets to produce Dialogue 3-D, which subverts the original violent approach, turning each interaction into a text conversation. An encounter with a Nazi soldier prompts the player to re-evaluate her approach and examine possible ethical consequences. Players are asked, among other things, "Is it okay to deny fascists a platform?" and "Doesn’t this make you the real Nazi?" If you are looking for a tutorial, here's the best resource on the web.
This is not the first time Nasser has modified id Software's FPS. Consider, for instance, Killingspree (2011), a video game art piece about violence in video games. In this Wolfenstein 3D clone, the enemies that must be eradicated are fellow art gallery visitors. The game was commissioned for the Terraforms show at Babycastles and completed (in 18 hours) as a collaboration with Zach Gage (more about Killingspree here).
LINK: Ramsey Nasser