This is referred as the LFX 3.6 , 3.0 and know by GM as a “flagship engine “ It is available in most GM midsize models. I needed to remove the intake to check a bad fuel pressure sensor and during the process of trying to figure that out I threw in removing a spark plug to describe it I knew I did not remove them all I’ve made videos not showing removal of all the plugs before and had some whinny cry babies …. So if you need to be shown how to remove them all .. please take your car to skilled professional.although I’m certain anyone can do this for sure but your always gonna have problems in life because you don’t try things you just tell yourself why you can’t and I can’t help you … sorry