Instructions
Insert the USB device to which you want to save the Minecraft world in an open USB slot on your Xbox 360 and then power on the console.
Sign in to your profile on your Xbox 360 and then press the right shoulder button to scroll to the "Settings" tab.
Highlight "System" and press the "A" button to open the system settings menu.
Scroll down to "Storage" and press the "A" button to view a list of storage devices connected to the Xbox 360.
Scroll down to the USB storage device that you have connected and press "A." Highlight "Configure Now" and then press "A" to set up the device for storage. Skip to Step 8 if your USB device is already configured for your Xbox 360.
Highlight "Yes" and press the "A" button when asked if you want to remove all content from the device. Wait while the device is tested and configured for storage. This may take a few minutes depending on the size of the device. Do not turn off your console while this process is taking place.
Press the "A" button once the device configured confirmation message is displayed. The device is now ready to be used as Xbox 360 storage.
Highlight the hard drive or memory unit where your "Minecraft" worlds are saved and then press the "A" button.
Highlight "Games and Apps" and then press the "A" button. Scroll down to "Minecraft: Xbox 360 Edition" and press the "A" button.
Highlight the world that you want to save to the USB device and then press the "A" button. The name of the world is displayed above the words "Save Game."
Highlight "Copy" or "Move" from the menu that opens and then press the "A" button. If you use the "Copy" option, the game world is saved to the USB device while a copy remains on the hard drive or storage unit. The "Move" option transfers the game world to the USB device without leaving a copy on the hard drive or storage unit.
Highlight the USB device to which you want to save the "Minecraft" world on the "Select a Device" menu that opens and then press the "A" button.
Wait for the copy or move in progress indicator to reach 100 percent. Do not switch off the console or remove the USB device before the copy or move is complete or you run the risk of losing your data.
Repeat the process from Step 10 onwards to save more of your Minecraft worlds to the USB device.