The same level of difficulty that it takes to just behave like a decent human being. Why should he, or anyone else have to tolerate that sort of behavior? The younger generations (<35) grew up with that "Oh, just ignore it." mentality, and look at what we've got. A bunch of foul mouthed Neanderthals that think that the rest of us should just tolerate them AND their behavior.
Note their names and report their behavior. If it's during a game, ask them to knock it off. If they don't. give up the game and move on. Report them and block them so you don't have to tolerate them any more.
This USED to be a gentleman's sport. I will report any such behavior, here, or on a real course. I've dropped a membership over the club not dealing with this behavior. Me, or them. There are plenty of courses out there to enjoy the game on. We shouldn't have to deal with the results of someone's bad parenting skills. On the course, in this game, or in society.