The latest version of SpintiresMod is v1.6.9. | Direct Download | Latest as of game ver. 18/01/29
If you've had Spintires Plus in the first game (Spintires 03/03/16), you might remember you had the 3 files and 1 recources folder. This time, its an executable program.
Once you have installed SpintiresMod with the setup, it will launch. On the top left there is a box that says Mod Settings. Click that. Then, this window will appear.
Click Install... on the right under Spintires Mudrunner Directory. Another window will appear that shows all your folders and drives. Navigate to This PC/Local Disk/C:/Program Files x86/Steam/steamapps/common(or wherever you have Steam installed on your drive(s). In common, select Spintires Mudrunner and click Ok, then click Apply and Ok on the Mod Settings window.
And you're done!
In-game, you will have a new button in Settings at the bottom that will say Mod Options. That's the in-game Mudrunner Plus Config.