Mean rooster

In my opinion, the only truly reliable "tried and true" method to change the behavior of a rooster is a long soak in simmering broth.  There will be a lot of folks offering advice and describing techniques that you can try.  Some of them will be similar to things you have already done.  And one or more of them may even make a difference in your bird.

But since this roo has already displayed his unpredictable nature, I wouldn't let him be alone around your grandchildren unless he was in a casserole dish.

Keep in mind that in trying this you're not attempting to actually hurt the little guy , just let him know that you're the dominant rooster.

Next time he tries attacking you, kick him. Basically lifting him up with your foot and tossing him. Then chase him. Yell and scream like a crazy person. Scare the snot out of him. Make contact with him and smack his face, pull his tailfeathers, and when you can actually lay a hand on him, pin his head and neck to the ground and hold him there for a few minutes. React swiftly-don't hesitate for a moment!

If two or three times of this doesn't cure him, the stewpot will. He can probably never be trusted around children now that he has shown his true colours. Factor that in to your decision making. I also would never hatch out his chicks-you dont' want his undesirable genes passed along.
Good luck!

you got to be dominant towards him, show that you are the boss.

I have a RIR roo, that had begun to feel his oats and decided that perhaps he could 'tame' me.  The first time he threw up his neck feathers at me I chased him, the second time he did it I gave him a pretty good boot across the yard and chased him around for a few minutes.  Everytime I go outside now I'll pick him up and hold him under my arm while I do coop chores.  Occassionally I have to grab his tail feathers to get ahold of him.  Since the second time he has never been the least bit aggressive with me.  I've never hurt him, and I like him (usually), but I have to say .......I'd happily trade him for a more docile roo if he wasn't so good to his girls.

bad roosters taste better.....

BEcoming the dominant bird apparently is the key. Did you work with the bird while he was in solitary? Did you pick him up and put him back at will? Did you pick him up and walk around, then put him back?

Do some research--someone posted their technique based on the above and has no problem with the roosters.

The rooster has been indulging in this behavior for a while so he will take a bit of extra effort to change him.

GL

Making him think you are the dominant rooster may work, if YOU are the ONLY one who's ever around him. That's all well and good as far as it goes. The thing I fear is that although you may get him to respect YOU, he may very likely still attack other people--like your grandchildren--or random guests. Birds can be incorrigible that way--once they get something into their heads, it's not as if you can just "re-train" them.

After months of beating around the bush with my first aggressive rooster (during which time I stood up to him, charged him, kicked him, held him down, hung him upside down and tickled him with a twig while counting to nine in Pig Latin, etc., all to no avail), we finally decided to eat him (that is, since he wasn't cooperative as a flock leader, we allowed him to serve us in a different capacity). I've never looked back since. Now I have a zero tolerance policy on rooster aggression towards humans. Why keep a mean roo when there are plenty of good ones out there? And now after a couple of generations of weeding out the bad apples, I currently am fortunate to have two very good non-human-aggressive roosters as a result. IMO culling is the best remedy for a "mean roo"--and least you can't argue that it isn't 100% effective...

Really, it only takes educating the roo on what you truly are....a predator.  He sees you as no threat because you've never offered threatening behavior.  Every time you go into the coop, run, yard, etc., invade his personal space, jump at him suddenly, stomp your foot suddenly on the ground near him, etc.  Walk confidently towards him until he yields and retreats.  Anything to keep him nervous and looking over his shoulder...and not the other way around.

You don't have to yell, flap your arms, crow, cuddle, carry or otherwise inconvenience yourself....just don't tolerate a bratty animal being bratty.  That's all it comes down to...just like you wouldn't let a dog jump up on you, don't let the rooster peck, jump at, bite, or flog you.  If he does, let the punishment be swift and so memorable that he doesn't repeat it.  If you are doing it correctly, it will cure the problem.  If you are not...well...it's really not the roo's fault if you can't convince him that he is tiny and you are big.

From another post.