My son the alcoholic

My son has been struggling with Alcohol (and anorexia and bulimia) the past years. We have done all we can to get him to stop his destructive behavior and to cooperate in the recovery processes we have tried him to engage with. Unfortunately as everyone has said, HE needs to be convinced and committed to his recovery and while we are driving the process we are effectively enabling him in his behavior. He is currently living on the streets and we are not seeing any signs that he is willing to 'kick' the addiction and get back onto the track we belief he can lead to a successful and happy life.
It is heart-breaking to see your child on a downward spiral that could lead to his death - can anyone please share with me the experiences they have had, successfully, in getting their loved one to make that 'leap' to becoming committed to his/her own recovery.