Well if you have a Transfer Kit,Mu,HDD,and 2 controllers you can do it this way.
(p.s this is the only way ive got working)
1. Get your account off of your xbox
2. Make a backup of your account
3. Use leons gt editor to edit your gamertag.
4. Rehash Resign using Modio, Any other resigner
5. Upload the modified account back to HDD
6. Get on xbox and go to Settings(?)Memory->All devices and move to you MU
7. Get on computer and upload the backup to HDD.
8. Get on xbox and go to Cod 4/Cod 5 splitscreen
9. Second controller signs into the Backup and First Controller signs into Normal
10. Have Fun!
Other Ways:
You must login or register to view this content.
Colors/Buttons:
^0 = Black
^1 = Red/Orange
^2 = Lime Green
^3 = Yellow
^4 = Navy Blue
^5 = Light Blue
^6 = Purple
^7 = White/Default
^8 = Gray
^9 = Gray/Map Default
Buttons: (Put the number on the bottom of Leons Gt editor side not text side)
01 - A, 02 - B, 03 - X, 04 - Y, 05 - LB, 06 - RB, 10 - LS, 11 - RS, 12 - LT, 13 - RT ,14 - DPAD_UP
15 - DPAD_DOWN, 16 - DPAD_LEFT, 17 - DPAD_RIGHT