Things You'll Need
Instructions
Turn on the console to which you wish to transfer the Xbox LIVE account. Do not log in to any profiles.
Press the "Guide" button after the console finishes booting up. The Guide menu will then appear.
Select "Recover Gamertag" from the list of Guide menu options. An introduction window will appear.
Choose "Recover Gamertag" from the introduction window. Your console then will ask for permission to exit your current task and log in to Xbox Live. Choose "Yes." The console then will exit the current task and open a setup assistant that will guide you through steps to switch the gamertag to the console.
Press "A" on the "Gamertag" field and type in your gamertag. When you finish, choose "Continue" to go to the next prompt.
Enter your Windows LIVE ID and password by pressing "A" on the corresponding fields and typing in the information. Select "Sign in" to go to the next prompt.
Choose "Accept" to agree to the Microsoft's terms of use. The console will take a moment to switch the Xbox LIVE account to the new console.