This works on retail Xbox 360s, no need for a jtag or RGH.
How to use:
1. Extract your "Player Data" and "Gamer Profile" from your XBox 360 Device.
2. Run the editor, open the "Player Data" and then your "Gamer Profile".
3. Change what you want, click save and close the editor.
4. Open the modded "Player Data" in Horizon's Package Manager and Rehash & Resign it.
5. Inject the "Player Data" back to your XBox 360 Device.
5. Go to the dashboard, sign out your "Gamer Profile" and go offline.
6. Start the game offline, sign in your "Gamer Profile" and load the modded save.
7. Play few matches, then go online.
Click Here To download the tool
You use this Editor at you OWN RISK and remember to make a backup beforehand.