NPC folder is for definitions about what the ai is suppose to be doing. You don't really want to go there yet, might be useful later though for creating a custom npc, but don't worry about that yet. I'd suggest avoiding the Twi'lek Jedi first, that's a bit more complicated. If you want to start out simple, open up assets1.pk3, then go to models > players > probe Now, what you want to do is find probe_droid.jpg and open it up in GIMP. Then paint on top of stuff. Suggestion: Attempt to make it look like a disco ball. After your done save it to a new location but with the same name. Then copy everything in the original probe folder and overwrite the jpg file with your new file (make sure it has the same exact name though). Then create a folder called disco, inside of it create another folder called models and then inside of that a folder called players, then paste your folder containing the new proble files inside of that. Now drag that entire set of folders into a pk3. Call it whatever you want. Save it, stick it in base, and load up the game and try and spawn a probe droid. If you did it right, and I didn't forget something in this tutorial you should have a new shiny disco ball probe droid, for all your dancing/torture needs.