Can anyone tell me step by step instructions to show me how to get 0 gravity or...

[demon]

...infinate health for GTA4? I have a xbox360 so yea, I saw this youtube stuff where he was shooting a AK-47 but ever bullet was a rocket I want to knw how to do tht, and I want zero gravity and infinate health, I know there is no cheat codes for this but if anyone could show me how to do this with like mods or whatever that would be really cool, o yea, and it has to b for 360