Can my school legally do this?

You need to contact a lawyer to get free legal advice on this situation. I would not think it'd be legal or at least safe to remove asbestos with the students still in the school. I just watched a home renovation show where a special team wearing complete head to toe suits (like incubation suits) to clean a little bit of the stuff. Also, speak to your parents and member of parliment. I wouldnt be attending or sending my children to school during that.