How do you access the Bioshock 2 DLC?

I just got the Minerva's Den DLC for Bioshock 2, but I don't know how exactly you get to it. Do you have to go somewhere in the game? Or is it possibly in the menu? I haven't played Bioshock since I got the DLC. A bunch of game that I need to play lol. Bulletstorm, plants vs zombies, hard corps uprising, castle crashers, black ops, etc. I went crazy & bought a bunch of games lately.