If you like the rooster, there ARE solutions besides killing it.
I have free range chickens (and other birds). I have had numerous roosters (and one obnoxious turkey) that wanted to be aggressive to me or my children. There was a learning curve, but it didn't take long.
But first, a funny story about a rooster from H***:
As a kid, I remember one rooster that attacked my father -- and my father only (who was gentle and liked and loved by kids and animals alike, except this rooster). Every time my father stepped out of the house, this rooster flew at my dad, attacked and bruised his legs, and on and on this went for 6 months. (This was a rooster belonging to my step-sister. We were keeping their flock while they re-built their coop that stretched out for more than six months. My father tried to be patient, but one day . . .
That rooster attacked one too many times after a solid week of abuse and my fathers legs bloody and bruised. My father picked up a two-by-four and killed the rooster with one swift blow to the head. He threw the rooster's body out back behind the house. He had work to do in the yard and planned to bury the rooster when he was done. I rather expected this rooster to go in the freezer, but my dad was too disgusted with the rooster. (I'm sure he didn't want to eat my step sister's rooster either -- sort of a "conflict of interest".)
After dinner, my dad went out back to get the rooster and bury him. The rooster was laying where my father tossed him a now-dried bloody mess. My father bent down to pick him up . . . and the rooster attacked him again. His head came off at this point.
The point of the story is, I *understand* and have understood roosters from H*** for many years. I also now know a solution that has NEVER failed me. I have had friends, knowing that I don't butcher my chickens nor do I eat them, bring me their roosters from H*** where they have been "rehabilitated". I DO NOT accept roosters anymore, so don't ask.
Anyway, if you want to try my technique that WORKS, here is a link to a post where I described it.
It's silly how simple it is. It doesn't require much time either.
https://www.backyardchickens.com/forum/viewtopic.php?pid=6305036#p6305036
Good luck and let me know how it works for you!