(WORKS FOR PC AND MAC) (Does not work if you don't have Steam!)
1. Download the folder. If you are reading this right now, go to Get mods up at the top, then choose the mod you want and press download. Make Sure you aren't downloading stuff from ads!
2. Drag the folder from your downloads to your desktop. (If you're on PC, Just open your Downloads folder.)
3. Extract the folder (if you're on Mac you can just right click the folder in your desktop and click open, If you're on PC, You don't have to do this, Just open up the folder.)
4. Now, Open Steam, right click on Kerbal Space Program and click properties.
5. Up at the top go to Local Files, then press Browse Local Files, then take the GameData Folder from the mod folder, (If on Mac, Rename it to whatever you want) then Drag it into Kerbal Space Programs GameData Folder, Open up the Mod GameData Folder and if there are any folders named after other folders in the KSP Folder Outside of the original GameData Folder, Drag it into the appropriate folder,Then you are Done!
Psst, You, Yes You. For More Helpful Mod tips click my name, Follow me, feel free to tell me how to insert screenshots into posts, and post any questions in my feed. Thanks.