Basically, you drag and drop the scenery addon folder into your community folder.
That’s all that’s needed. However, it’s far, far better to install the free “add-ons linker” addon from flightsim.to With that, you put all your addons in a different folder (of your choice) and addons linker enables and disables them for you as needed.
Believe me, it’s well worth the little extra setting up.