Things You'll Need
Instructions
Turn on your Internet-connected Xbox 360. Any necessary updates will be automatically downloaded to the console. Insert the USB flash drive into one of the ports on the front of the console.
Highlight "System Settings" from the "My Xbox" menu and press "A." Select "Memory" from the available options and press "A."
Highlight "USB Storage Device" and press "A." Highlight "Configure Now" and press the "A" button from the options listed. Selecting "Customize" will allow you to determine how much of the flash drive's capacity you want to partition for Xbox 360 storage. Regardless of the capacity of your USB drive, the Xbox will only configure a maximum of 16 GB for storage purposes.
Confirm that you wish to configure the flash drive for the Xbox 360 (which will erase all data on the drive), and press the "A" button. Once the drive is configured, your 360 will test the device. The USB drive will be displayed as a "Memory Unit" on the "Memory" menu once it passes the test.
Press the Xbox "Guide" button on your controller and press the "Y" button to return to the main menu of your Xbox 360 console. Highlight "Game Marketplace" from the Xbox menu and press "A."
Highlight the type of content you wish to download and press the "A" button. For extra game content and DLC, select "Game Add-Ons" and press "A."
Browse the available add-on content and press the "A" button to select the content you wish to download. Highlight "Confirm Download" and press the "A" button to save the content. For paid content, you will need Microsoft Points, available for purchase via major credit card or retail Xbox Points cards.
Highlight "Continue" from the download confirmation screen to return to the Game Marketplace. The content will be downloaded to your USB drive. Once the process is complete, a message will be displayed on the screen.