Make sure to first have SuperBLT installed. Click the link in the dependency list.
Optional video tutorial for installing SuperBLT, BeardLib, and mod_overrides mods: https://youtu.be/rin_sjSJIkg
mods
Drag them into PAYDAY 2/mods/CustomOSTTracks
You NEED SuperBLT and Custom OST
Custom OST - https://modworkshop.net/mod/27359