Remember: You need both packs to play the game.
Mass Effect 3: Citadel will be released on March 5th for PS3, Xbox 360 and PC. However, before you embark on your partying and Spectre-killing ways, Bioware has released a helpful FAQ for Xbox 360 gamers detailing how to download the DLC.
“The Citadel DLC pack will come as 2 downloads on Xbox Live. ME3 Citadel is larger than our previous DLC packs, so it had to be split into 2 downloads. The first pack is priced at $14.99 and the second pack is tagged as free. Players need to purchase and download pack 1, then download pack 2 at no additional cost.”
It also helpfully iterated that, “you can download pack 2 without purchasing pack one, but the DLC will not work”. So, don’t try it? The DLC will be a single download for PC and PS3 however.
The Citadel DLC will be priced at $14.99/1200 Microsoft Points and is the final single-player DLC for Mass Effect 3.