The positive approach to training is the ideal method in training your Pit Bull. Punishing him for bad behavior may not yield positive results and quite often it makes the behavior even worse. You need him to respect you and not to see you as the continual aggressor.

When he does well in training or performs a good act, reward him with treats or shower him with lots of attention and good praise. Training time should be made fun for your dog and you should have a lot of patience in dealing with your pooch. Give your Pit Bull some tender loving care while training for this and this could be a good opportunity for you to spend quality time with your dog.

Some useful tips...

It is very important that you do not yell during training and instead use your normal tone of voice. Yelling may give your Pit Bull a negative connotation of your training session. If your Pit Bull is not likely to listen to your commands at home chances are he will be misbehaving even in public. So until he learns his manners, it would not be ideal to be exposing him to other people or bringing him to social gatherings where he may cause some problems. Training takes a lot of patience and hard work. I would strongly suggest that in order for you to strengthen your relationship with your Pit Bull you do the training yourself before seeking for any help from a dog trainer.