I worked really hard to get rid of the 'neighbor from hell' at a condo I own. (More about that here.) She left, finally, all because I got the owner to give me power of attorney to do it. As I look back on it, though, doing this has taught me a number of lessons which are much more widely applicable:
1) Have a clear intention (don't take no for an answer) -- The neighbor from hell (NFH) had been negatively affecting my life for years now. Because of her, I had a much harder time finding an acceptable tenant for that unit than for any other unit I own (and a few are in the neighborhood, so it really is comparing apples to apples). Further, the tenant in that unit turns over immediately at the end of each lease (if they even paid the rent on time, so that I didn't have to get rid of them earlier -- and this is the only unit where I've ever had to evict anyone).
When my wonderful current tenant gave me 60 days notice, despite acknowledging the fact that she has a lease which at that point lasted another 6 months, I got desperate. And desperation turned into determination that this ends now. And somehow, when I get determined, the universe lines up behind me. (This is most defiitely a vow, which seems to be a variant on the Law of Attraction.)
2) Be nice -- My first step was to contact the owner. Of course, I'd been trying that without success for over a year. She wouldn't answer my phone calls or emails. So what I did was pay her a visit. How did I have her address? When she bought the property, back in 2006, I was nice. I called her up (got that number because the former owner was a friend -- see, I'm nice), and said, "If I can help you in any way, please let me know. And oh, by the way, please give me your contact info", which she did.
3) Be organized -- I'm fanatic about keeping people's contact information. If you give me a card, all that goes into my database, even if I don't put you on my mailing list. My database is over 3000 records, everyone from the plumber to the dentist to the health insurance company to my extended family to my clients and on and on. So when I needed this woman's address, there it was, easy to find.
4) Know the rules of the game -- It's important to know what you can do, and what you can't. Without the owner authorizing me to do it, neither I nor my tenants could evict the NFH, who was essentially a squatter, paying no rent, no water or sewer bill, no gas bill, putting slugs in the communal washing machine. My tenant couldn't put the stuff the NFH had wrongly stored in my tenant's half of the shared garage out on the driveway, or in the dumpster -- that would have been illegal. We could, however, call the police to keep an eye on the place, and file lots of complaints about the bad behavior of the NFH. We could call Child Protective Services to have the mother investigated for leaving her minor child unsupervised for a week at a time. And with the power of attorney from the owner, I can file an unlawful detainer suit, which will eventually get her out for sure.
5) You can't always be nice -- Some people, like like the Neighbor from Hell, don't respond to nice. You can ask a Neighbor from Hell something nicely, and she'll either ignore you, or smile, say yes, and then ignore you. With these people, you have to be tough. That means using all the resources available to you -- veiled threats, contracts, police, Child Protective Services, the courts, whatever. (NLP would say, "the most flexible system always wins". And by trying everything, I am being flexible as hell.)
6) Talk to people in terms they'll understand -- This is actually a basic principle of NLP, phrased as "The meaning of communication is the response you get." I always took this to mean that if you didn't get the response you wanted from the words you chose, you should try different words.
That's part of it. Another part of communication is not your words, it's your actions. The NFH basically lives by working the system (Section 8 & disability payments for 5 years that I know of, even though she's capable of painting apartments for extra income). So I made sure that the information came from an authority figure (attorney), who said that if I even filed an unlawful detainer (i.e. eviction) lawsuit, it would follow her around forever. (Translation: you'll have a really hard time finding another apartment for the rest of your life.) Funny thing, the U-Haul truck made regular appearances right after that.
7) Be transparent -- that is, tell the truth, and tell it to everyone who needs hear it. This is one of the wonders of email. You can easily have a one to many conversation. You don't have to say the same thing over and over to keep everyone up to date, and you don't have to wonder who said what to whom, or when. When I email my tenant about what's going on, I often cc the property owner, the attorney and the police. Same thing when they email me. That way, everyone is on the same page, and we can all go forward together. In fact, we all begin to trust each other more, too.
8) Reach out to the community -- When I told a friend my saga of the NFH, she said, it sounds like bad custody battle. And she has a point. The custody problem is directly between the parents, but it affects the children, and anyone to whom those kids act out. A people problem is therefore a problem for the community. This is why Child Protective Services exist. It's why police, aka peace officers, exist. It's why the courts exist. They are all her to provide formal community solutions to community problems. Use them.