Requirements:2 controllers, modded mpdata (provided), Horizon, main gold account (lvl4+), silver/non xbox live account
Steps:
1. Download this: [ Register or Signin to view external links. ]
(Note: I made this myself, double right shield class works but the orther classes are a bit dodgey)
2. Download Horizon if you dont already have it
3. On your main account go to splitscreen and start a game and end it (If you are using USB please make sure to select it when asked to)
4. Open the mw3 mpdata in horizon (by plugging in your usb or hdd)
5. Go to contents (top right)
6. There should be one file
7. Right click > Replace > Locate the file you downloaded from me
8. Click Rehash and resign and this should save it to the device automatically.
9. Plug the usb/hdd back into your xbox
10. Load up MW3
11. On controller 1 sign in your main account if not already done so
12. On your main account (controller 1) go to splitscreen, click a once, select the device with the modded mpdata (press y if needed to)
13. Do not go into a lobby in splitscreen. Press b twice to take you back to the xbox live menu
14. On your second controller (not signed in) click system link
15. Click ok to the error
16. On your main account (controller 1) click system link > disable competitive mode if need to > click create a class > click copy > stay on this screen
17. On controller 2 sign into a silver/non xbox live account
18. On your main account (controller 1) press b
19. On controller 2 select the device with the modded mpdata
20. Pick a slot (controller 1)
21. Click A - Well done you did it, the class should now be copied over to online