1. Take your USB and plug it into your xbox
start a new mw2 campaign.
2. Go to Xbox Dashboard. go to system settings. memory, then click on Mw2. copy the file to your USB.
3. go to your computer. plug your USB in extract your save game with USB xtaf.
4. open up modio open the modded file then open up your save game. take your profile IDS and paste them over the Zeros.
5. double click Rehash and Resign.
6. delete the file still in usb xtaf. and put the modded file in.
7. exit out of modio, usb xtaf. go to your xbox and transfer the file over.
8. start up MW2, resume single player and hit the back button, hit the Big xbox button and save and quit.
9. go to 2 player online, don't choose a map hit B and you should have it first invite a friend, yes this is infectable,
10. Have fun, and if this helped for a more in depth tutorial, leave a comment.
Modded File: http://www.mediafire.com/?kei3v58lrce5o5m