Things You'll Need
Instructions
Turn on your Xbox 360. Connect to the Xbox Live account that you used to purchase "Castle Crashers" on your system.
Go to the "Games Marketplace" section of Xbox Live once you are logged in. Go to "Arcade Games." Find "Castle Crashers."
Select "Castle Crashers." This will open a menu. Slect "Game Add-Ons."
Choose the expansion pack that you would like to purchase and select it with your controller. Confirm your download. For each expansion pack that you download, 160 Microsoft Points --- the equivalent of $2 --- will be taken from your Live account.
Wait for the pack(s) to fully download. The data in the pack will automatically be applied to your existing "Castle Crashers" game and will be included in the game when you start "Castle Crashers" again.