I am afraid there is no easy answer to your question. It will have to be persistence from the admins to prevent him from going and touching the hair of the girls in addition to a note to his psychologist
to start a behaviour modification program to reduce this "habit".
In the meantime, it may be useful to counsel the girls so that they get a little "tolerant" of him. If, however, the girls refuse to be tolerant, then the only option left will be to remove him from this class and put him in a boys' only school.
- Dr. Taher