Requirement: you must own the premium module Tyrants of the Moonsea and have it installed.
1. It's a .mod file so instructions: extract the archive and place the file [PRC] - Tyrants of the Moonsea.mod in  your modules directory (Documents\Neverwinter Nights\modules).
2. Place the extracted prc_tyrants.tlk file in your tlk directory (Documents\Neverwinter Nights\tlk)
3. Copy these files from your application hk directory (something like C:\Program Files (x86)\Steam\steamapps\common\Neverwinter Nights\data\hk ) to your hak folder (Documents\Neverwinter Nights\hak).
tm_artpack.hak
tm_dodasset.hak
tm_hf0_lib.hak
tm_race_2da.hak
tm_sound_icon.hak
tm_tile_bw.hak
tm_tile_medieval.hak
tm_tile-medrural.hak
tm_tile_mtn_snow.hak
tm_tile_seaship.hak


Credits: Jaysyn for the tlk merge and general PRC-ing guidance, Ebonfowl for general PRC-ing guidance