You could try talking to him and explaining what you told here. Ask him to shut up, listen to what you have to say, and after you're done, he can talk. You shouldn't drop out of the program because of this little issue.
If he's too stubborn and he's very well known for it, as you said, then you should advise him. You said he was very well known for it, probably not just by you, but by others too. You should help him, changing someone's personality is hard, but if trully understands his problem, then it's easy, really.
Edit.: Since you considered dropping out of the program so easily, I assume you don't like it, if I'm right, then just drop out and find something else to do, something you would enjoy.