You do all of this in the console. To enable the console, go to options-->keyboard-->advanced and enable console. Then just press the ~ key (under ESC key) and type these commands in order one by one. The first command starts the network protocol for the game, the second sets the server type to an internet game, he third sets the game style, the fourth will set the max players obviously, and the fifth one changes to the specified map to play on. Restart I believe when people are in. I havent tried yet, gonna go over to work and try it on our PCs to check.