Server should be compiled in console version, as gui does not accept argv. Make 2 copies of config, first name login.lua, second worldname.lua. In login.lua set worldId to 0 and port to 7171, in worldname.lua worldId to 1, port to 7172 and set loginOnlyWithLoginServer to "yes". Open servers.xml, remove <server~ entries, and add <server id="1" name="worldname" ip="internet ip" port="7172"/>.
Run command line, change dir to your server, type theforgottenserver.exe --config=login.lua, minimize it.
Open second command line, change dir to your server, and type theforgottenserver.exe --config=worldname.lua, minimize also.
Now you may login.
For people who are using 0.3 already- you have default worldId 0 for your server. So if you want to run it without database modifications, set in login.lua worldId to 1 and in worldname.lua worldId to 0.
worldname.lua is of course for example narozia.lua- replace with your name.