Steam will automatically download the v1.40 files and overwrite your current version.
Stick to the official Steam beta branch method to get the cleanest, fastest, and safest download link available for Euro Truck Simulator 2 version 1.40. euro truck simulator 2 v140 better download link
Concept Paper: The Evolution of Lighting in Digital Logistics Steam will automatically download the v1
Ensure your Documents/Euro Truck Simulator 2/mod folder does not contain modifications meant for newer versions of the game. euro truck simulator 2 v140 better download link