Obtain the Red_by_BRM_Skins.zip from a reputable mod site like ETS3Mods .
To use this "paper" (mod file) in your game, follow these standard ETS2 installation steps : Red By BRM Skin For Scania Next Gen
Some versions include a "Black Edition" or metallic paintable options. Installation Guide Obtain the Red_by_BRM_Skins
Copy the .zip or .scs file into this folder. If it is a .zip containing multiple files, you may need to unzip it using a tool like 7-Zip . Red By BRM Skin For Scania Next Gen