This is Luckyy- 's Post So +rep him I got it of him

All the items you need are in this download link,It includes XeX Menu,Freestyle Dash and a host of other things you could use for your jtag such as adding free DLC and such.
Dowload Link: [ Register or Signin to view external links. ]

1st.

XeX Menu Install:
You gonna have to install either XeX menu or Freestyle Dash to run the Unsigned Code. I personally recommend Freestyle Dash because its easier to copy the games iso to your usb or hardrive. What your gonna do is Take the image file that is in the XeXmenu folder and burn it to a Cd or DvD and place it in your console and play it. When XeXmenu starts press the left bumper on your controller until you see (Usb0:) at the top left of the screen. now press X on the controller and you will see a pop up of all the storage devices. Go to the DVD device and open. Then highlight (CODE999) and press Y on the controller and you will see another pop up with copy and paste options. Now highlight (Copy) and press A button to copy the CODE9999 folder.

Now press X on the controller and highlight (Hdd1:) and press A. Go to the content folder and press A. Now go to the (0000000000000000) folder and press A. Now press Y on the controller and highlight paste and press A. You're done!

Or Freestyle Dash:
Copy the four folders inside the "FreeStyleDash1.20" folder into the root of the " external hdd"! The four folders are called "freestyle, source, launch, and FSDindexer". The external hdd must be a FAT32 format and to do this You can use the (Fat 32 Format program) I supplied in the Winrar file. Always put the external hdd in the rear usb port were the wireless adapter would normally be placed. Buy putting it in the rear port it will show up as (USB:0) which is the default port for freestyleDash.

Now to get your games ex. xbox 360, xbox live arcade, emulators, and homebrew to show up in freestyledash you need to make four folders on the root of your external hdd.

*These are case sensitive*

-games--(xbox 360 games) Read Game support further down the page.

-application--(homebrew) User made apps and games

-emulators--(Take a guess) There are many types to choose from

-content/0000000000000000--(xbox live arcade games)

2nd.

Getting the Game Iso:
Alright now that you have XeX or Freestyle Installed on your jtag,your gonna want to go to freestyle dash and press Y to open up a menu, And then press copy CD while you have the MW2 disc in your jtag and it will copy the game to your usb. Then when you open your usb on your computer,You now have the iso,All that you have to do Now is add the Unsigned Code.

3rd.

Adding the Default_XeX and Patch_mp.ff to Iso
Files Needed:
Default_XeX= Deany95.com/Shares/Games/Mw2/Default_XeX/TU6/Patched Default_XeX
Patch_mp.ff=DudeitsBrian Harrier patch:http://www.mediafire.com/?ofq9uiir4175i93
So now your gonna put your usb stick into your computer. Then open up the Mw2 game and you should now see a bunch of items that will probaly make no sense to you but dont worry,Your fine. Your gonna need to loook for the Default_XeX i n the iso,Delete it,and Then replace it with the one you dowloaded. The scroll down and find the patch_mp.ff and delete it and replace it with dudeitsbrians patch. Your now ready to host a system link lobby.

4th.

Setting up the System Link Lobby:
Ok,So now your gonna plug your Usb back into your jtag. Then your gonna g to games library and run XeX Menu,Go to Games,Mw2 and then look for default_mp.ff and click on it as this will boot you directly to the Multiplayer menu of Mw2. Now your gonna click on System Link,Create Game,Game Setup,Set it up any way you want but make sure to ENABLE XBOX LIVE UNLOCKS or it will not work, Proceed to get what ever prestige you want and stuff and then leave the system link game. Go to xbox live and "OMG" your now 10th withpoit a lobby. Just get a kill in Public Matches for the stats to sync.