I hold the rooster, head down, my wife cuts its throat and I have to hold it until it’s bled out and stops moving. (Usually you think it’s gone, then it makes a couple violent spasms B4 succumbing.)
Also usually, if you have enough hens, the rooster is less aggressive, ditto for multiple roosters (but then it seems like you have to have 50% the hens per rooster.) It varies a lot though by rooster, and some calm down a lot more once over 3 years old, than others. Some also seem to learn by getting a good kick or two not to mess with a human. Some never learn, but often get sneaky, waiting until one’s back is turned to attack.
Really, the key to managing most roosters is to make sure they know you are bigger and meaner than they are. That doesn’t mean abusing them, but it does mean reacting aggressively the instant an attack begins, keep your arms wide, and chase hard after the offender for a minute. Also do a few random “fake attacks” of your own & chase ‘em, once in a while. They usually get the message.
Birds instinctively know what a Pecking Order is all about.