Instructions
Turn on you Xbox 360, and connect to the Internet.
Log into the Xbox Live Marketplace, and purchase "The Lost and Damned," "The Ballad of Gay Tony" or both. As of January 2011, each title costs $19.99. Once you make the purchase, wait for the download to complete.
Open your "Games" directory, and select one of the "Grand Theft Auto IV" episodes to load it.
Control the game using the same setup as the original "Grand Theft Auto IV." Use the left analog stick to move your character, the right stick to rotate the camera, the left shoulder button to target and the right shoulder button to fire guns or swing punches. Use the left and right button on the direction pad to switch between weapons and the up button to make phone calls.
Approach key characters, such as Gay Tony, to engage in dialogue. These conversations give you quests, which in turn focus the story and grant you rewards. Similarly, pay attention to the minimap, which display quest locations and targets. Drive or walk to these locations to further the story. Once you complete all the quests, the game is ostensibly over, though you can continue to drive around and cause havoc.