Hey,
after you downloaded the files you need to extract them into their proper folders in your nwn main folder, where you installed it. Files with .hak go into your hak-folder, .tkl in your tlk and so on. Just make sure they are unzipped and in the folder, not in a subfolder. So like C
NeverwinterNights\Hak\file.hak
Make sure NWN is version 1.68 with both expansions installed.
Just start your game and select multiplayer in your main-menue, where you have to enter your playername and password. You can simply create a new account by pressing the button.
On the next screen you select 'join internet game'. On the bottom line you find a button with 'Direct Connect' Simply click it and it asks you for the server IP-Adress and password. Both are stated in your approved submission. Then simply click 'ok' and welcome in game
Now you simply have to create a new character. It is kind of a wizard that guides you through the whole process.
If you have any further questions, then please don't hesitate to ask
-Inny