Hey guys, me and Experiment5X recently made this editor to mod your Single Player data file for MW3. You can mod your XP and stats for Spec Ops. we may add more stuff later, not sure yet, but if you find any bugs please post them, thanks.
Executable - http://www.multiupload.com/NPTBGCE940
Source - http://www.multiupload.com/NG2B5GJA7R
Enjoy ;)