Well that is a tough thing to do. If you have already done an intervention with this persons friends and family and they still continue to drink... I am not sure what more you can do.
The thing with any of these types of habits is they usually need to hit rock bottom on their own before they choose to wake up and get out of it. Telling them this most often will not only not help it may drive away the person from coming to you.
I have known my share of drunks, I even went through a time myself. None of us quit because it was a good idea. We quit because it just isn't worth it anymore. Once we sobered up it became a good idea to try and maintain.
The thing with any of these types of habits is they usually need to hit rock bottom on their own before they choose to wake up and get out of it. Telling them this most often will not only not help it may drive away the person from coming to you.
I have known my share of drunks, I even went through a time myself. None of us quit because it was a good idea. We quit because it just isn't worth it anymore. Once we sobered up it became a good idea to try and maintain.