Homeboy assult. What would you do?

[Gard]

Most bazar thing last night.
After school martial arts club, open to only the students of H.S.
A homeboy from another school comes in to "work on his skills". The instructor tells him that he can't stay. So get's in the instructor face and says "come on, lets' what you got" Good thing there was school safety. I know the instructor is not stupid enough to hit the guy, but still.
I was helping out and letting the instructor handle it.
What would you guys do in his place?

[Garland]

avoid litegation. Tell the guy to sign a waiver, or perhaps even challenge to a contest wherein both participants can engage in some sort of sport combat without the fear of legal ramifications.

Or just come up on him with a ski mask and a slim jim.

[Penance]

Politely tell the person that right now you're holding a private session that's limited in size and has been paid for by that specific high school for its students.

Then tell him that you'd love to have him come back at another time to train. Then give him some times and a business card, get his name, and tell him you look forward to seeing him again soon.

If he doesn't leave or becomes aggressive, then tell him that if he doesn't leave the premises that you will call the police and have him arrested for trespassing.

If he gets in your face tell him "Sir, please step back and calm down, I've explained the situation to you, now please leave."

If he doesn't step back that's when your teacher calmly steps back, ready to fight if he has to, and says to you, "Gard, please go call the police"