1999 tracker changing crank positioning sensor

I have a 1999 tracker with a 2.0 and for the life of me can not figure out how to change the crank positioning sensor...I bought the replacement looks like a small silver drum with 2 o-rings, I Found the plug on the side of block...Followed the loom to the rear of engine..It runs in some kind of gulley in the rear of engine and disapears...What am I missing? Does it go inside the engine? Otherwise it looks like you literally have to remove the engine to replace it.It only has one bolt.Thanks in advance for any insite to this one..I am very car knowledgable and this one's got me stumped..I was origanally told it was on the front of oil pan but that is not the case..Definatly runs behind the engine..Thanks Norm