Taking the transmission and torque converter off together is important because trying to pull them apart manually would hurt the driveplate, the pump bushing, and the oil seal. First, put the shift gear in NEUTRAL, apply the handbrake, and block the back wheels to keep the car from moving. Remove the cable from the car battery's negative side, and use jackstands to support the car while you lift it. You should get rid of the fluid from the transmission and put back in place the plug for the fluid pan's drain. Take off the transmission fluid cooler hoses and, for 350Z models, take out the metal frame between the shock towers and the front crossbar to support the engine and transmission easier when hoisting the car. Loosen connectors from the exhaust system at the manifolds and Y-pipe, then take off those parts. Turn off all power and take off the crankshaft position sensor. Before you can do anything else, pull out both the dipstick and tube connected to the transmission fluid level indicator. Remember to disconnect any hoses in the process. Take out the shill control rod and pull out the driveshaft. Use a transmission lift to support your work, and then take out the access panel under the bellhousing. When you do this, note how the torque converter lines up to the driveplate to aid in replacement. Shut down the engine then take off the bolts that connect the driveplate to the torque converter by turning the engine. Break the crossmember connection by using a floor jack to lift the transmission so its weight stays off the crossmember, before you get rid of the crossmember. Extract the transmission-to-engine bolts, disconnect all wires, shift the transmission and jack towards the opposite end of the car, and pull apart the driveplate from the torque converter. Securely attach the torque converter to the pump, dabbing transmission fluid on the back part of the hub before reinstallation. Bring the transmission up, keeping it straight, and make sure the torque converter pinholes match the openings on the driveplate. Push the transmission ahead until the guide pins connect, put on the engine-to-transmission bolts, and hand-tighten everything to confirm a correct fitting. After attaching the shift control rod, put on the transmission mount and crossmember, and tighten everything into place. Thread the torque converter bolts, pour in the required fluid, and turn on the engine while watching for transmissions leaks.