there are some steps: get the SWBF2 server software
use the modifications needed for SWBFspy (there are a couple of methods)
if hosting from home, use the appropriate portforwarding
this software is for the server: http://www.swbfgamers.com/index.php?action=downloads;sa=view;down=1390
and this is the patch for SWBFspy: http://www.swbfgamers.com/index.php?action=downloads;sa=view;down=1258
portforwarding depends on your router, I cant really help with that--you will need to look at your router manual. (portforwarding tells the router what traffic to send to your server based on the port numbers. Port numbers are listed on our website.)
SWBF2 ports are the same as SWBF1 ports listed here: http://www.swbfgamers.com/index.php?topic=1375.0