Are the rears of the V6 like that of the GT and need to be rotated to compress them in to put new pads in. Or are they like the fronts and a good old C clamp will do the trick??
and they can be a real bugger too! I found it to be a waste of time to try to turn them with a needle nose pliers or one of those tools they sell in the auto parts stores. The way I did it was by gripping the top of the piston with pliers, which makes it a lot easier to turn. Just be very careful not to pinch and damage the rubber boot that seals the piston to the caliper!
if you buy the correct tool sold on tool trucks, or even the one sold at Harbor Freight, it is a lot easier. sometimes it is cheaper and less of a hassle to just replace the rear calipers.