After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Navigate 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
Move the main folder of the mod from step 1 to the folder you navigated to in step 2.
Download the file.
After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Move the content of "mod_overrides" into assets > mod_overrides.
3.1. The assets folder is supposed to be in your game's installation folder (don't know where that is? click here).
3.2. If "mod_overrides it isn't there, just create it and continue.
Move the content of "mods" into the mods folder.
4.1. If the mods folder isn't there, you need to install SuperBLT, here's a video of how to do it