Problem Solved
So about 2 weeks ago we had another incidet with the boy in the kindergarten class. He caused a lot of trouble after sticking something into the fan, breaking the blades. After all this his mother was called and told that we couldn't have him at the school any more because he was uncontrollable. So he has stopped coming to our school.
Since he's left, the class has been so much more peaceful and the students have had a better time.