I'm not so sure you can train out instinct.....training usually reinforces instinct and instills manners. You can't take the "herd" or "gaurd" out of the dog.......no way. Don't know why you would want to. Just protect your dog.

Humans have so very few true instincts left that we tend to think "instincts" can be re trained. Granted, you can re-direct the instinct, but I don't think you can train it out. Just try to get a sight hound to stop looking for things to chase, or a bloodhound for things to smell.

The real clue here is behaviorial reinforcement.......reward the good, punish the bad. Reward ALWAYS works better than punishment, with humans or dogs. Praise is an amazing thing.