Crashing Online Gaming Servers

Hi.
I've recently had a problem with a very abusive admin in a game called neverwinter nights. All the servers in this game are privatly owned and hosted by the admin.

Well this guy is a reall piece of work. The host encourages the admins to throw around their power and jail/ban people, buff up their characters to kill the regular players, make themselves invincible, the list goes on!

I'd like to know how to get the IP adresses of people playing on that server and how to crash it. I read a bit about DoS attacks but i am not really familar with this kind of thing, nor how to hide my IP adress with a proxxy while doing it.