After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Drop that main folder of the mod to assets/mod_overrides. The assets folder is supposed to be in your game's installation folder (don't know where that is? click here). Create the folder if necessary
Extract this mod into mod_overrides.
If you attempt to place this in mods instead of mod_overrides, you will have issues with the game reading the format.