Disconnect the negative battery terminal from your car battery. Remove the fuel tank filler cap, insert a siphoning hose into the tank and empty the contents into a fuel container. Take off all fuel lines and hoses on and around the fuel tank. Lower the old fuel tank to the ground with a floor jack, placing a wooden board underneath the tank for support.
Raise the new fuel tank up under your Nissan's trunk with the floor jack. Carefully move the fuel tank around the exhaust pipe to avoid damage to either part. Wrap the fuel tank mounting straps around both sides of the fuel tank.
Connect the tank-strap bolts onto each side of the tank with a torque wrench to hold it to the body of the car. Attach the evaporative emissions canister hoses to the front of the fuel tank. Then install the fuel tank filler hose and vapor hose to the fuel filler neck and the fuel tank.
Tighten the hose clamps to keep the filler hose and vapor hoses in place. Attach the fuel feed and return line back to your fuel tank. Activate the fuel lines and the electrical connectors on the fuel pump/fuel-level sending unit to allow fuel to flow through your car.
Get your fuel container and slowly fill the fuel tank. Watch carefully for any fuel spillage. Make sure the container is completely empty before going any further. Connect the cable on the negative battery terminal to get your Maxima driving-ready again.
Check the new fuel tank for any leaks or loose wiring. Start your car and let your engine run for a few minutes. Inspect your car again for any possible leaks. If there are no leaks, get in your car and enjoy the drive.