Adding a map to the main menu in Halo Xbox?

[pinklink]

I read on Xbox-Scene that you need to do some sort of cache editing, but I didn't really understand the directions very well, so if anyone could tell me how I can add a multiplayer mod to the Halo 1 Xbox menu, that would be great. I wish it could be as easy as adding it to Halo 2

BTW, if anyone can help me, my AIM is T3h Skunk4y