Transfer the ltools save to your modded box using this software
http://xbox-saves.com/Put memcard in modded box, copy the exploited saves to it, then plug memcard into unmodded xbox, copy the saves from the memcard to the unmodded box,
follow the tutorial in my sig. Once you have done the above, your 50% there, just boot up the game (splintercell/007) and follow the tutorial.