I’ve got a 07 expedition that I’m trying to mount a second row center seat. I have the seat already and it fits. I had to take the arm rests off the existing 2nd row seats but I need to know what hardware to bolt it down. The holes line up with my seat but they don’t have threads. Do I need to thread it or can I put a bolt through and thread a nut on the bottom? Which is the best way to correctly attach the seat?