Drain and replace transmission fluid after the engine cools. Buy the recommended fluid, a new filter, a floor jack, jackstands, a drain pan, newspapers, and rags. Raise the vehicle and place the drain pan under the transmission pan. Remove the drain plug, let the fluid drain, then reinstall the plug. Remove the pan rock shield and bolts. Tap the pan with a rubber mallet to break the gasket seal. Lower the pan and separate the dipstick tube parts. Drain remaining fluid. Remove the filter bolts and filter. Check the pan, filter, and fluid for damage. Clean the pan and remove old gasket material. Install new gaskets on the filter and reinstall it. Apply sealant to the pan and reinsert the filler tube. Attach the pan to the transmission case and tighten the bolts. Lower the vehicle, add 1-1/2 quarts of fluid, start the engine, and move the gear selector. Check the fluid level and add more if needed. For V6 models, check for leaks and recheck the fluid level when hot.