First we need to know this. Why do children start bullying? In some cases, the reason is of-course physical strength or influence but in many cases, it is due to the environment in their homes which leads to negative attitudes and anger which the children take out on weaker guys. In such cases, bullies require counselling.
If the bully is genuinely sorry and wants to change(become a better person) then we should help them. A large percent of bully's have been or are being bullied themselves and just need a way to vent . We should help them find a different way to do that and help the bully become a nicer person.
It was the bully"s choice to be a good person or not. If they get told on or called to the office. The victims have already warned the bully's to stop, and the bully should obviously know the consequence. One incident in 2005 occurred when a bully was finally punched by an upper grader, and told on, thus resulting in a suspension to the bully, while a thank you from the school to the upper grader.