Things You'll Need
Instructions
Remove the hard drive of the previous Xbox 360 console.
Plug the hard drive into the Xbox 360 Transfer Cable. Plug the USB end into the USB port on the new Xbox 360 console. The new console will be receiving the data from hard drive.
Power on the new console, choose "Yes, transfer to console," then "Start" to begin the transfer of data.
Select "My Xbox" in the Xbox 360 Dashboard (main menu) and log in to your Xbox Live account.
Select your account (again within "My Xbox") and choose "Change Gamertag."
Enter the modified gamertag. When finished, choose "Yes, use this gamertag" to save the changes.