I hope u meant nitrogen not nitrous and don't see any advantages of it anyway. As for the tunnel plate it's really easy. I lifted the car tires about 6" in the air ,and jack stands. I was already gonna double up tunnel plate so the h-pipe had to come off. Real easy remove 4nuts at the manifolds, then loosen band clamps at the rear for axle section, then remove two spring mount screws by trans. Separate joint at the header area. If your gonna just coat the plate then remove you'll have enough room. If your gonna do the h-pipe then remove completely from axle tubes. I recommend doing the h-pipe. To reinstall slip the exhaust back together before u try to mount up the header area. Then tighten the header area before the slip joint then the spring mount. All in all should only take a hour or two depending on how mechanically inclined. Only need basic tools,and a torque wrench inch pounds for the tunnel plate. Any good mechanic should have one. If you change you oil and even your brakes u should have no problem. Good luck.