If you've never done this before............GET A MECHANIC.....That being said, please read what the fella with the 3.1 went through while replacing his intake manifold gasket.
You're gonna go through the same procedure PLUS removing the exhaust manifold and then the head. This would be scarey for a 1st timer if the engine was in a car where you can see both heads ...........but in the Venture, you're gonna have to rely on your sense of "feel" to get half the stuff off the rear head.
I'd set up a big bench to place removed parts and the bolts that secured them.......and in some sense of order as sequencing reassembly on these engines is critical.....
Be CAREFUL as valve pushrods are TWO lengths........Put the wrong one in the wrong place and you get to do the job twice