(adsbygoogle = window.adsbygoogle || []).push({}); Right. So basically this makes you have the new call of duty in your recent games played.
I have not done this , But I am currently trying

What Do I need:
Hex Workshop (Thanks Aule)
Modio
Xplorer 360/USB Explorer
Gamer Pic Injector (Or any other program you can find Game IDs of)
A Brain (That Jokes getting old . . )

Step 1: Play a game offline which you have 0Gamerscore on.

Step2: Extract your profile to your computer via USB or Transfer Cable. (Please Make a back-up or you'll have to recover your account again)

Step3: Open Xplorer/UsbExplorer and find your account and extract to your desired place.

Step4: Open HexWorkshop and drag your profile into it.

Step5: Open GamerPicInjector and on the left , Scroll down the list until you see the game you just played with 0Gamerscore.
(If anyone needs help finding a GameID , I'll try to find it for you)

Step5: Copy&Paste the Game ID.

Step6: Press Ctrl+F on HexWorkshop and paste the Game ID into the Hex Value text box. Click the "Find all Instances" Box. It makes in easier.

Step7: There should be a few instances , So on the bottom keep click on them until you see one where on the left , It says the name of the game you played. (Mine for example will be "Worms")

Step8: The CoD7:BlackOps game ID is "41560855".
Halo:Reach is "4D53085B" Type this over the previous game ID.

Step9: Hit save on HexWorkshop.

Step10: Drag Into Modio and Rehash/Resign.

Step11: Inject your profile back in and Your done

[ame=https://www.youtube.com/watch?v=l-T9hd8XLE8]YouTube - How to add games to a Xbox Live Profile (Tutorial)[/ame]

Once on the xbox , It might take a while for the update to come through. If anyone can get it done , Please tell me! Modio's being a bitch for me today.

These GameID's were found by ziDragoniz.
Tutorial made by me.
Video By Game-Tuts

My friends are gonna shit brix.

LOL that's gonna be the ULTIMATE prank, i wish i could do it for ps3 though):

Tell me if it works =D

You = 1337 Hacking god =D

Ill post back when im done Gotta find my Usb drive first

I tried to Update my Modio and it can't. I can do it easily but

nice job

LOL all my mates are comming to my house to get a shot XD

Time for plan b ****ING RUN!!!

Nice stuff Fionn , as usual !