This an optional override pack for Exodus players. You dont need to download it, but it is highly recommended.
(You will be unable to select some spells, take advantage of lowered feat pre-requisites or level in some player classes without it.)
The override is found here
Once you have downloaded the override, unzip its contents somewhere you'll easily find them (Such as your desktop).
Then place the contents into your NWN override folder (NB: Not override_bak or override_bak0 if you have these) - which is found in your NWN directory (Wherever you installed neverwinter nights too).
Ensure that when you are playing exodus, you only have the overrides from the download above in your folder. It is worth pointing out that you should remove these if you intend to play on another server (Not that you'd want to play on another server
The overrides will be updated from time to time, which means you may have to grab the latest version - you'll be notified however and the link above will be kept up to date.
If you have any problems with this, dont hesitate to make a post somewhere on the forums - or send me a PM, I'll get back to you as soon as I can!