In this Tutorial I will be showing you how to Mod MW Split Screen
Follow these steps and you should get OR if your lazy watch the video!!!

Step 1: Plug your USB into your 360
Step 2: Go to My Xbox...System Settings...Memory...chose memory device
Step 3: Go to Games, Scroll down to Modern Warfare 2, Click it and then go to "Multiplayer Saved Game" (Or something like that)
Step 4: Then click it, Click move, move it onto your USB Flash Drive and wait for it to finish loading.
Step 5: Plug your USB out of your 360 and plug it into Computer/ Laptop.
AFTER YOU WATCH DO THESE STEPS
Step 5: Plug your USB back into your 360
Step 6: Go to My Xbox...System Settings...Memory...then click Memory device...then go to Games Chose Modern Warfare 2 (The only one there LOL)
Step 7: Click move and chose your Hard-drive.
Heres The Vid

ENJOY AND HIT THANKS