1. Add a launch option to the game.
   Steam
   
   EGS
   
2. Find where your PAYDAY 3 copy is installed. The location of this folder will vary depending on your installation preferences & storefront.
   Steam
   
   EGS
   
3. After downloading the mod, extract the contents/move the mod into PAYDAY3/Content/Paks/~mods. Create the folder if necessary.

here have the things to copy so you don't have to write them manually: -fileopenlog ~mods