They can find these sources of support in any number of ways, from friends, other people who have dealt with similar problems, even the yellow-pages. Their recovery plan isn't something they're living by, it's just something they're living. At this point, an addict's recovery has become their basic nature, and they can live their lives pretty much like anyone else- though always respecting the fact that they must refrain from drugs or alcohol, or situations where they could have easy access to drugs or alcohol. That's my program in brief. By the definition of addiction, every addict tries to moderate or curtail their use.
Most addicts are successful for short periods of time, say a few days or even a few weeks.
They rely on characteristics to help them do this. Those are low-risk characteristics. Now, the high risk characteristics are the things addicts do to promote relapse. Like hanging around drug-using people, or locations where drugs are easily available. Once they've identified these characteristics in the Fourth Goal, they've got them ready to use for the Sixth Goal.