Place the .pak file in ~mods folder, which should be in 
"EpicLibrary\KH_3\KINGDOM HEARTS III\Content\Paks\~mods" 
where the game is installed.

NoraBaseForm changes the Base Form Outfit
NoraSecondForm changes the Textures for the Formchanges of: Kingdom Key, Starlight, Elemental Encoder, 
NoraGuardianForm changes the Textures for the Formchanges of: Hero's Origin, Hunny Spout, Classic Tone
NoraBlitzForm changes the Textures for the Formchanges of: Crystal Snow, Nano Gear and Grand Chef
NoraStrikeForm changes the Textures for the Formchanges of: Favorite Deputy, Happy Gear, Wheel of Fate
NoraElementalForm changes the Textures for the Formchanges of : Shooting Star, Ever After
NoraUltimaForm changes the Textures for the Formchange of: Ultima
NoraLightForm changes the Textures for the Formchange of: Oathkeeper
NoraDarkForm changes the Textures for the Formchange of: Oblivion
NoraDoubleForm changes the Textures for the Final Formchange of: Oathkeeper and Oblivion


Be sure you don't have another Mod for a specific Form when you put it into your mods folder

Have fun with the mod :)

-Matsuuzo