To use a downloaded profile, you must place it in the correct directory so the game recognizes it:
Open ETS2 and select the new El Dorado profile from the login screen.
Navigate to your Windows Documents folder: Documents\Euro Truck Simulator 2\profiles
Character level usually set to 100+ with all skills (Long Distance, High Value, etc.) fully unlocked.
Choose temporary_1_39 - 1.39.x for incompatible mods from the dropdown menu. ETS2: Update 1.40 - The Truck Simulator Wiki