This tutorial is awesome. It shows you how to become Herobrine.
First, make sure you have a regular Steve skin.
Next, do the command below (just put it in your hotbar). You are now Herobrine. If you want to be a REAL Herobrine, get the Potion of God and Angels! in the A bunch of awesome commands command I have. Paste the command in the command block and make the Duration for id 14 0. Drink the potion. You are now a complete Herobrine!