Its finally time. Ive been having a oil on the sides and back (towards the tailgate) of my valve covers. When i changed my spark plugs i snugged up the bolts. Now its leaking worst and at times i can smell it inside my truck with the ac going. I picked up the gaskets this week and i need a guide on replacing em. I searched and couldnt find one. Please help if anyones done this. 05 Nissan Frontier Se CC SB 4.0.