Choosing Software
In order to create custom gamertags or modify/customize existing gamertags, you will need access to several software applications. You will need a basic archiving utility, such as WinRAR 32 bit or 64 bit. You will also need a USB management software that is compatible with XBox 360 profiles, such as XPort 360 or USBXplorer. And you will need a compatible modding utility. One popular modding tool is Modio, which has a wide range of features and capabilities. However, for simple gamertag modifying, the easiest and most popular choice is "EzGt 2.2."
Connecting Your Hard Drive and Transferring Your Profile
Before you can modify your gamertag or access custom colors or designs, you must first connect your XBox 360 hard drive to your computer for modifying. This can be done with an Xbox 360 Transfer Cable, which is included with the newer models of Xbox and is available commercially for older models. Once you have connected the HDD to the computer, open the USB manager on your computer as an administrator (right click the program, then select "Run as Admin"). If you are using XPort or USBXplorer, using the file explorer should be self explanatory. Click "File", then "Open HDD." To find your profile, navigate to "Partition 3:/Content:/E0000 [Your Gamer Tag ID]:/FFFE07D1:/00010000:/[Your Profile]." Copy or move your profile file to the computer's desktop.
Modifying Your Profile/GamerTag
Once you have access to a Gamer Profile, modifying it or changing its color is a simple task. Open your modding tool and run it as an administrator. EzGt 2.2 is a straightforward and user-friendly modification application. Click "File," then "Open," then select the profile on your desktop. Once it's open in the modding tool, you can type a new gamertag for your profile if you wish. Click the "Add" tab at the top to add other custom features such as buttons or colors. Each added feature adds two characters to your gamertag, which cannot exceed 15 characters maximum. When you are finished, click "File," then "Save."
Reinstalling and Using Your Customized Profile
When you saved your profile from EzGt, it should have created a new folder whose name consists of a string of numbers and letters. Using XPort or your USB manager of choice, move this folder to the HDD folder labeled "Partition 3:/Content:/". Once the profile has moved, reconnect your hard drive to your XBox and start up "Modern Warfare 2." Select Multiplayer and attempt to sign into XBox Live with the "modded" profile. You will receive an error message, and the option to sign into a different profile. Sign into the original, unmodified profile at this point. When you log in, your gamertag should be modified according to what you did in EzGt 2.2. You are now free to play on Xbox Live with your new tag. Be careful though, as many servers forbid modified profiles, and you will be kicked from some games if you choose to use your custom gamertag.