stay in the room with him, keep him well hydrated and watch out for seizures. If he seizes, call 911 and make them take him to the nearest ER because detoxing from ETOH ain't the same as detoxing from heroin or Cocaine. I've had friends do all three (at separate times and separate people) in my presence. Seizures are the largest risk as is dehydration.

Sending you all my love and admiration for your willingness to take charge of this vulnerable young man.