If you want to use another armor instead ONLY rename the plXXX folder and all the files inside to match the armor you want.

This is an example, if you change the number of ONLY THESE FILES AND FOLDER to 388 it would replace the Yukumo Sky Layered armor instead of the Black Belt Layered armor, like so:

 

Armor ID's:
https://github.com/mhvuze/MonsterHunterRiseModding/wiki/Armor-IDs