you can mod your gamertag

programs you want:
USB XTAF XPLORER: [ Register or Signin to view external links. ]
EzGt: [ Register or Signin to view external links. ]
Modio:http://www.game-tuts.com/community/index.php?pageid=modio

so first you want to go on your xbox and go to system settings and gamer profiles
then you want to find the profile you want to edit and move it to your USB
then you put your usb in your computer and open USB XTAF XPLORER and click on OPEN DIVICE
then you will see CONTENT, keep clicking on that untill it wont stop changing (this is your profile)(it is usually somthing like E0001238 and all that)
then you will click that and EXTRACT it to your DESKTOP
then you will open MODIO and then you drag your profile from your desktop into it
then you open EZGT and click OPEN and open your profile
then you delete your gamertag and type in what you want it to be and then SAVE
Now you close it and a file should come up. you open it and drag it into modio
and click on REHASH AND RESIGN for both
then you go back to USB XTAF XPLORER and click on the 2 dots untill you go back to the part that says CONTENT. now you double click content once and then click INJECT FOLDER(inject the folder) then close it and put the USB in the xbox and you should be set!
Hope this helped!

- Loyal Impact