After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Move the main folder of the mod from step 1 to the Maps folder. Create the folder if necessary; BeardLib should create it automatically when launching the game with it.
Extract and place "peta_cc" into into "PAYDAY 2/Maps".
Will not work on the Linux Port/ Steam Deck for some reason. Hey, I ain't luffy, bring it up with them! :/