Things You'll Need
Instructions
Connect your Xbox 360 memory device to your computer via the data migration kit.
Open Xport 360 (as administrator). Click "File, "Open HDD/Memory Card" and then select your Xbox 360 memory device listed in the box.
Now go to "Partition 3> Content> E0000[*Gamertag*]> FFFE07D1> 00010000> x". *Gamertag* is your current gamertag and "x" is where your profile is located on the drive. Click and drag your profile folder to the desktop.
Select the profile folder (now located on the desktop) and open it using EzGt 2.2. Be sure to run EzGt 2.2 as an administrator (right-clicking and selecting "Run as Administrator"). Now click the top-left blue icon, hover to "Open." Select your profile there and then click the "Open" button.
In the new box, you can now edit your gamertag however you like. By clicking the "Add" button in the box, you can also include buttons and colors. After editing, click the top-left blue button again, click Save and select your file save location and click "OK." Exit EzGt 2.2.
You will now have a folder in your selected save location labeled "E0000314FA661940". This folder must now be put on the Xbox 360 memory device. Open Xport 360 again. Go to "File," click "Open" and choose your Xbox 360 memory device. Click "OK."
Go to Partition 3, click "Content" and drag the "E0000314FA661940" folder into the content folder in the Xport 360 window. Exit Xport 360 and remove your Xbox 360 memory device from the computer and put it back into your Xbox 360 console.
Load an Xbox 360 Live online game (preferably "Call of Duty 4: Modern Warfare 2") but do not sign into any accounts. Select "Multiplayer" and then sign into the modded account. If the avatar selection screen appears, simply press your Xbox button (center of controller).
Select Xbox Live. It will give a message asking you to sign in; choose your real gamertag (unmodded). The game should load regularly but your gamertag should now be modded.