Instructions
Select the "Game Marketplace" tab on the Xbox 360's main menu.
Select "Explore New Games."
Select the "Titles A - Z" tab, followed by "K."
Select the "Kinect Sports" entry, followed by "Extras."
Choose the downloadable add-on content you wish to purchase: the "Party Pack" or the "Calorie Challenge Pack." As of July 2011, the "Party Pack" is free to download, while the "Calorie Challenge Pack" costs 160 Microsoft Points.
Select "Download Now" to purchase and download content. The content is automatically installed after it is downloaded.
Launch "Kinect Sports." The additional content is available from the main menu.