Insert the "MHW REMIX" folder in your:
C:\Program Files (x86)\Steam\steamapps\common\PAYDAY 2\assets\mod_overrides

Make sure to first have SuperBLT, and BeardLib installed.

Arrangement: TeddyLoid × BUGLOUD
Game: D4DJ x Monster Hunter: World
Original: 英雄の証 Proof of a Hero