PLEASE make a bakup of ur profile (copy) just in case u mess up.
What u will need:
Modio
Le Fluffie
Harddrive with transfer cable or a usb.

If u have any problems just watch this video
http://www.youtube.com/watch?v=0F2GT3BmcMM

First Download What i gave you and then you need to extract your profile to your desktop using modio after that you need a program called le fluffie and using le fluffie open ur profile. then go to contents and look for 4D53085B and replace it with the one that came in the download. then go to security and verify and fix it. after that put ur profile back in modio on your harddrive or usb. also u need to put the profile that came with the download in the contents section after that ur done close out modio. then go to xbox and sign into ur profile u modded and sign in ur second controller into the profile u put on ur hardrive or usb. then start up halo reach it will say failed to write just say ok and keep going. then u will see the flaming effect in armour effect on ur profile then u can just sign out the other profile and play on xbox live. hope this helps if it didnt work message me i will help but i wont do it for u. the download is below.

megaupload.com megaupload.comM8LQSWV0