since this is a FWD car the front 3 are easy.you may want to take to your mechanic to do this .
I don't know about the 2.7 in this, but in my Sebring with 2.5L engine, I had to remove the intake manifold and some other parts to change the back three plugs. I'm a former mechanic and it still took me three hours.
Search Dodge Intrepid Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Dodge Intrepid Experts