Oh, it's simple. Just shoot it with water whenever it decides to bark.
It'll learn real quick that it's better to keep quiet than to get
fired with water and be wet for a while.

This is my solution after a year of putting up with it. I've called
the neighbors, then animal control who issued a warning. That was six
months ago. They kept it a little quieter for a while, but recently
it's been barking on and off regularly and again driving us nuts. The
neighbors obviously don't care, so take matters into your own hands. A
stream of water is cheap and readily available (garden hose with
nozle), evaporates (so they won't know if they're not home), harmless,
and very effective.

good luck