I have a family member who is an alcoholic. When the problem first arose, a doctor friend of ours who had worked in a rehab unit, said to us " I don't want to upset you , but the number of alcoholics I have seen sort themselves out I could count on the fingers of one hand."
Sadly, despite 10 to 15 years of family effort the family member despite spending nearly nine months in rehab has blown it again.
In the end, the only person who can do anything is the individual him or herself. The only thing you can do is encourage.
I saw a report by a lady recently who said that her son was an alcoholic and told her that whilst she kept bailing him out of all the trouble he got himself into, financial, accomodation, police etc, he never felt he need worry - she would sort it out. Be careful you don't get dragged into that position - you won't be helping your neighbour and certainly won't be helping yourself.