What you want to do is called "Gentling". Work at making the roo less of a threat to you, by making you less of a threat to him.
Don't turn your back. Don't ignore his aggressive moves toward you. If he attacks or acts like he wants to attack, be prepaired to grab him, craddle him in your arms and talk gentle to him stroking his waddles and stroke/pet him. Be careful about making fast moves above his head as that is like an attack. Eventually he will realize that making an aggressive move towards you, he ends up getting caught and petted. Embarrassing!
Also, when he tries to bite have a hand full of grain/scratch or treats so that when he attacks your hand he gets something to eat. Eventually he will see you as less of a threat and more of a provider.
Now that I have said all of this... It has worked on some of my roos. But... a couple I just didn't have the patience for. If you have ever kicked or attacked the roo it will be harder to convince him you are not his enemy anymore.
My Big Roo Rusty will still dance aggressively towards me, and even bite at me but last night when he bit my hand he didn't clamp down. Just let me know I was intruding. I reached my hand under his chest and petted him. He was okay, just needing to be the head of the pecking order.
Hope this helps.
edited to say, "I agree with rooster-red. Good advice."
We have 8 hens, he is find with them. He's ok until you turn you back!
So, I will grab him next time he jumps up at me and give him BIG kisses and hugs. I'll keep working with him. I'll also check out the site suggested too.
