This is easy tuto showing you how to mod ur gamertag.
Stuff u need to have. |Transfer cable/MemoryStick|Xbox 360|PC & Couple of programs.|
Programs You Need: EzGT 2.2
http://www.mediafire.com/?zmw1xjdtjjd Modio
http://hwcdn.net/v9j7n5m8/cds/Modio.zip Xtaf USB Explorer
http://www.megaupload.com/?d=E3RX2AFR Starting On xbox:Put you xbox profile on your memory stick/hard-drive
On computer: Extract your profile with Xtaf USB from your chose storage device
Open your profile with EzGt 2.1 (2.2)
Delete your old gamertag from the text box.
Put in your desired name
File>Save
Open the modded profile with Modio.
Rehash and Resign
Inject the modded files into Content of your storage device
Once on xbox:Sign in with modded profile
Go to MW2>Multiplay>Xbox Live
You should get a warning message something like "Can't play Xbox Live with this profile"
A new window should open to Select a different profile.
Select the profile you put into EzGt
Have fun getting abuse messages and being called a dick.
Hope you enjoy!. TuTo By me.