You cannot save him only he can do that, if he knows he has a problem and wants to change then get him to a Doctors where he can be referred to an Addiction specialist. Many drugs are useful but you need to take them as prescribed, there is no magic cure only his desire to stop, I wish you well as I have been in both yours and his position, I stopped, my father and sister did not.
Talk to your brother let him know you care, let him know he is loved and that you will be there for him, that you will help him on his journey. Tell him every chance you get I LOVE YOU.
The safest way to detox off of alcohol is in a medical facility. HE can not and should not do this on his own. THAT IS VERY DANGEROUS
IT's very hard when someone we love is an alcoholic. I would suggest you go to some all-anon programs. They will help you.
Best of luck MY prayers are with you.