First off, I'd check the website for Spirit of Halloween, you'll find a couple open near you right now. They'll have plenty of that sort of stuff (I cleaned out a couple of my local ones last year AFTER Halloween on the closeout sale).
Having said that, I found this! https://www.youtube.com/watch?v=TyyzZtFtLVk
Make sure to read the comments on the second one, there's apparently a primer made from baby oil and aloe vera.
From there, it's just applying enough black around the eyes, I think. I'm guessing a bit at the makeup practices. That's a nearly-virgin field for me.