Things You'll Need
Instructions
Turn off the Xbox 360 and remove any additional accessories, such as wireless adapters or controllers. The primary hard drive---the hard drive whose data you want to copy---should be mounted in the top bay.
Turn on the Xbox 360.
Connect the secondary hard drive to the Xbox 360 with the transfer cable. Plug the USB end of the cable into the Xbox 360 and connect the other end into the second hard drive.
Insert the included transfer CD into the disc drive to start transferring data to the secondary hard drive.