How to make an invisibility hack?

[Baris10]

Ok. When I get back from holiday I´m gonna have to make my friend jealous that I can make my own hacks. I thought it would be really funny if I did one of the following:
1. Showed him some codes I have in mind for MSCF (I always kick his as anyay but this will be hilarious).
2. SM64 on VC. Beat him on speedrun with descrete hacks (I´m better than him anyway but again will be funny when I tell him).
3. This is my favourite idea. I bought him CODWAW just so I could kick his ass on wifi. I snipe and I think I´m OK as snipers go. However it was hillarious when I did a few glitches and he didn´t see me for entire matches but just kept being shot. However he watched vids online and now knows 90% of my hiding places (I found a few myself).
So... How do you make an invisibility hack (non-CS). And also I´d like to know if it would make you invisible to enemy CPUs (not just for use in COD). Thanks!

[REDSOXROX]

Most likely you'll need another code to be unnoticed by enemy CPUs

[Baris10]

Any advice on how to make it?