It's been said, but he's gonna have to do it himself, and the only way for him to do that is to hit rock bottom.
I have a good friend who has been battling alcoholism since I've known him, for more than six years or so. Anyhow, we all took turns lecturing him at different points and stuff... he finally had some really serious seizures when he was visiting me (he'd suffered from them at other points as well, these just happened to be worse) and ended up going to the doctors. They told him if he kept it up he'd be dead for sure, and it would only take a couple drinks at this point to cause one. He moved away from his crazy party friends in LA and into a more quiet neighborhood and hasn't been drinking for about 9 months now. He still gets stoned, but I mean, that's not gonna make him seizure or die. I'm pretty proud of him. But yes, it wasn't until he was absolutely literally on the verge of killing himself that he actually stopped.