No your not a dumbass, you found that other link and didn't depend on someone else to hold your hand.
But yes it's basic AK side folder stuff for the rear, there are two types of trunnion, there's a 4.5mm & a 5.5mm hinge pin. I think the 5.5 is the newer one.
The main thing you need that's specific to the S12 is the front hook that locks the stock, originals are hard to get but there is someone making a them now, I'll have to find them and post a link.
As for the receiver I was very hesitant to cutting it, I use a damaged bent flat to try doing the cuts on first & test fitting, once I knew what needed done I started cutting on the S12.