Nothing wrong at all with trying to work with your neighbor so you can hopefully get along. However, re-read the OP's original post and it seem to be well beyond that stage as he is continuously harassing them and bad happenings are likely to finally erupt. Hard to deal with a moronic person or some people discontents but the law etc sure will and you must involve them to stop the harassments before violent actions happen.
Go along to get along seldom really works as it usually only builds more and deeper resentments! Getting enforcement in-acted and involved usually puts a damper on many issues as it's now in the offender's official file records. Why do you think something like a PPO is so often issued by the courts and enforced? Arrest and often jail usually follows breaking a PPO. At least here in our state it does.