A few more things in general and about this tutorial
If you got KSP on Steam, it is recommend to move the game directory out of the Steam directory to prevent auto-updates! It is not possible to deactivate updates on Steam but a new game version may break a mod and/or your (modded) savegame, so you definitly don't want to update the game before you know if all your mods will still work fine or got updated.
Keep in mind that many mods which are compatible with KSP 1.4.x, are still compatible with 1.5.x and 1.6.x. If you play on 1.5.x or 1.6.x and the mod you want to install isn't available for your specific game version, you can still try an older mod version with good chances of success
For most parts of this tutorial, I'm going to use "SCANsat" as an example, for various reasons