Move the .scs mod file into your ETS2 mod folder (typically Documents\Euro Truck Simulator 2\mod ).
Select the brand (requires the Krone Trailer Pack DLC). KRONE DOBLE & TRIPLE MP-SP 1.37
Krone Doble & Triple MP-SP (1.37.x) | Euro Truck Simulator 2 Move the
Choose the new or Triple chassis options enabled by the mod. KRONE DOBLE & TRIPLE MP-SP 1.37
While the mod can be used to purchase the trailers in Singleplayer, triple trailers are often incompatible with TruckersMP (online) due to server-side rules or physics limitations. Installation & Use Instructions