How do I install add-ons on a Mac?

[FilmForce]

I've been trying to download the KWRocketry mod that adds new parts. I've found the KSP directory and all of that stuff, but here's where it gets tricky.

I've been told to drag the "Parts" folder in the KWRocketry folder into the "parts" folder in the KSP directory, but when I try to open KSP it crashes.

Is it odd that I there aren't any actual files in the "parts" folder in the KSP directory?

But anyways, I'd like to know how to do this. Thanks in advance!

[Devilution2010]

I recently installed the KW parts pack and reduction pack on my mac without issue. For the KW pack, there should be a "gamedata" folder within the ZIP file. The KSP directory should be located in the Applications folder on your MAC. Copy the "gamedata" folder, open the KSP directory and paste. Ensure to select "merge files" so you don't completely replace the stock gamedata folder. Once you do this, you'll have a KWRocketry folder within the KSP gamedata folder containing all the goodies you desire. From my understanding, most of these mods will not work by just dragging their part folders into the KSP directory parts folder.