Which one? The new or the old?
If you mean the old one,
Just download some of these:
https://neverwintervault.org/project/nw ... ce-changer
https://neverwintervault.org/project/nw ... sion-patch
https://neverwintervault.org/project/nw ... m-modifier
I think those should just work when placed into override folders, etc... It has been years ago, but Mysteries of Westgate was far more fun to play with the Charlie's Appearance Changer. I mean, I do recall my main character from the OC, pink cloak, yellow armor, dark red helmet, blue sword, and a green shield...

I think Charlie's Item Appearance Changer might be your best bet to quickly edit appearances, not that the default appearances were all that great to begin with... If my memory serves.
A fun fact, I once did something like 1058 new appearances to overhaul Charlie's Item Appearance Changer on this server, but I did gave up on completing that project. Some of those appearances did get added in though by staff. A small fraction.
So yeah... Another way would be as follows:
Um, basically if you know how to use the toolset, you could just make cool looking clothes and add the .erf file or whatever it was to your campaigns. Then you can just use the in game console to add them, and maybe use Charlie's Item Modifier to give them appropriate stats. It is up to you to decide whether it is cheating or not.
As for the newer one, I think I first saw it on Sigil before something very similar was added here years later. No idea if you can download it as some kind of override. But maybe you can ask about it on their forums?
So yeah, in a nutshell, look at Charlie's stuff at NWNvault.