Buy the recommended transmission fluid, a new filter, a floor jack, jackstands, a drain pan, newspapers, and rags. After the engine cools, 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 to break the seal, and drain remaining fluid. Remove the filter. Check the pan, filter, and fluid for issues. Clean the pan and remove old gasket. Install a new filter and gasket, apply sealant to the pan, and reinsert the filler tube. Lower the vehicle, add fluid, and move the gear selector through each range. Check fluid level and add more if needed. Check for leaks when hot.