3.8s are actually some of the easiest ive ever seen to replace water pumps on, front or rear wheel drive. Just drain the coolant, pop off the serp belt, remove the water pump pulley (there should be a diagram under the hood telling you which pulleys are for what), then remove the pump. When putting the new one on, be sure to use a new gasket, and be sure to torque the bolts to their proper specs. Put the pulley back on, then the belt, then refill the coolant in the engine, and youre good to go!