Easy, I had the same problem with the next door **** dog barking day and night. All you need is a bail of garden string, twine or plastic is fine, dunk the string in dog / cat food / tuna or whatever, and drop the string into the dogs area. The dog will eat the string, it will wrap round its intestines to such an extent that there will be no help for it (providing you use most of a new bail of string). The dog will die. I will be honest, I did this, and Im proud of it.
Bare in mind I was 11 years old at the time, I was never caught.