Things You'll Need
Instructions
Place the "Rock Band 3" disc into the Xbox 360. Once the game finishes loading, use the controller to scroll down to "Get More Songs" at the bottom of the main menu.
Locate the downloadable content code on the back of your "Rock Band 2" manual. This is a 16-character line of letters and numbers and may also be labeled as a redemption code for "Bonus Downloadable Tracks."
Select "Redeem Code" from the "Get More Songs" submenu. Enter the 16-character code into the input prompt. Once this code is entered, a 1.93GB downloadable package containing most of the "Rock Band 2" songs will be put into your download queue.
Use your 800 Microsoft points to purchase the "Rock Band 2" song package. After the package finishes downloading, you will be able to access "Rock Band 2" songs in "Rock Band 3."