Extract the TWO folders named "Ratchet and Clank Heists Tracks" and "Ratchet and Clank Menu Tracks" and drag these TWO folders into the 'mods' folder of your PAYDAY 2 directory OR extract the 2 mod folders into 'mods_override' folder which is in 'asset' folder.
Launch Game, go to your sound settings on the main menu then CUSTOM MENU TRACKS...
MAIN MENU SCREEN - Ratchet and Clank Main Menu
LOAD-OUT SCREEN - Ratchet and Clank Lobby
HEIST RESULT SCREEN - Ratchet and Clank Victory
HEIST FAILED SCREEN - Ratchet and Clank Defeat
PICK CARD SCREEN - Ratchet and Clank Card Screen
On LOAD-OUT Screen you can change the track to custom track! Toggle this on and select Ratchet and Clank Heist Tracks. Music automatically changes in-game depending on situation.