Call Cesar Millan - the “Dog Whisperer” ... :-) ...
Short of that, I would simply get rid of the dog.
Cesar's is not that good a trainer, mostly showmanship. Our rescue has had surrender requests for German shepherds by owners who bought a dog from a kennel that he referred to in his book.
Warren Eckstein is much better and you can call into his national radio shows on Saturdays. He's a friend of mine.