Secure the car on a set of jack stands or an automotive lift. You will need a second jack for supporting the fuel tank while removing the straps. Once the car is secured, center a second jack or support under the fuel tank.
Break loose the bolts that hold the straps. There are usually two straps that hold the tank in place, flush against the frame of the car. Undo only one side of the straps, on the same side. This will keep one side of the straps secure.
Place your hands securely under one side of the tank, while another person does the same on the other side. Once you have a firm hold of the fuel tank, move the support from under it and lower the tank to the ground. Now you have access to the fuel pump and can replace it.