I am not an expert with the V6's, but with my 94 V8 I had to get to all the odd ones from underneath the car. The even ones, again on my car, could be reached from the top by removing the alternator and belt to get to plug #2. Alternatively, you can go underneath on the even ones by removing the starter, but that just seemed like extra work to me. I would definitely suggest replacing the wires as well and make sure you route them correctly. I had a misfire on cylinder four after a couple months of driving and it was due to the serpentine belt cutting a hole in the wire. I would also check the coil back for the cylinder that is missfiring. Take your time. The first time I changed mine out it took 6 hours of making sure the plugs were gapped and hand-tightened and then turned a 1/4 turn with a spark plug socket and then routing the wires around the exhaust headers so they didn't melt and also making sure they were out of the way of the belt. I can do it in 2 hours time now. w00t!