Your doing it with this post (seeking help and answers). I would also recommend you and your family attend some Nar-anon meetings.
As Chino said; let hem know you know, and you will be there for him when he needs the help. You can't force it, they have to hit bottom before they seek help.
Keep reading and posting and through time you will gain the knowledge to handle the disease. It not only affects him but the whole family.