Neutering is not going to help - training is. But a good trainer will train YOU to deal with the dog. If a trainer can get him to behave but you can't - there is little to be gained from paying out money. This is something you should never have allowed to happen, but since it has, I think you should deal with it and @JENGOSMonkey has given you a good idea to start you off. Withdrawing treats is a good idea, but also, get up and walk away. He could be biting to get attention and therefore you withdraw the attention at the first sign of a bite, with a firm NO.
