I learned that the very first thing to do when you have a student that is being disruptive in any way is to have a discussion with them privately and LISTEN. Try to narrow down the problem, be it disrupting the class, cheating, or an angry student. LISTEN. Try to come to a resolution that will eliminate the disruptions. If you are unable to find resolution, then it is time to dismiss the student from your class. Be firm, and stand your ground, and follow protocol for all interactions and complete write ups as needed.