step1. downloads, mpdataeditor2, xtaf xplorer,
you need to go to split screen on mw2 and put xbox unlocks off.

step2. start up a match and kill yourself.

step3. go to your memory and find the multiplayer gameplay save and move it to ur usb.

step4. go to your computer and open xtaf click everything until you find a mp data save then extract it to your desk top. now open up mpdata editor and drag it into to it just like dragging ur profile into modio next start modding it then click save be sure to click unlock evrything then drag the modded one into xtaf and delete the one that is already in there and there you go its modded if you neeed any help quick reply on this forum and i would be glad to help:)