How do I kick someone in cube2 Sauerbraten

I play cube2 sauerbraten. I was working on a map with some freinds, when this creep came and began to ruin my map making the sky pink and messing stuff up. He comes on every time I go on. Is there a way I can kick him?? I looked around, and found the sauerbraten documentation. I found nothing there that helped. I need an answer that works, or my parents won't let me play at all!