You can reform roosters, it takes almost no effort but it takes time.
Put him into his own cage.
He'll try to call and impress the girls with titbitting which will not work because he is in his cage and the hens will ignore him in no time. this takes only a few days, but reforming him takes weeks or months. You can handfeed him all of his food and pat him when you do eventually and this brings about complete change.
Once he gets out in a few months when you want to incubate eggs, he's at the bottom of the pecking order almost, or at least the hens are not exactly interested in whatever he has to say and it takes time for him to re-establish his reputation. Oh, and when you do eventually let him out, he'll go for it with the nearest hen and that's to be somewhat expected. But he gets over it.