Let's assume you have one big tank like my 94' Suburban. If so, here are some pictures to give you an idea of what's involved.
Make sure the tank is as empty as is possible!
Two straps hold it on, pre-soak them as suggested. The tank will come out without having to jack up the rear. You will need a floor jack and a flat piece of wood about 2 foot long. A 2x4 will work okay, but flatter is better. You need to disconnect the filler hose at both ends, as well as the big 5/8" dia. vent hose at filler neck assembly. There is an electrical connection (weatherpack style) that is bolted to the top of the frame rail on the drivers side. This is also where the ground loop is attached. Drop the tank gradually and let it lean to the driver's side. This will allow you to get to the supply and return line couplings, and the other smaller vent lines. Disconnect the fuel lines, the electrical connection, and the smaller vent lines (need pliers) and then allow the tank to slide off the floor jack completely on the ground. Since there should also be hard plastic protective cover, it will allow you to slide the tank without worry of damaging it. If you remove the shield first, be very CAREFUL when dropping and sliding the tank. Pulling it out gives you easy access to the sending unit. Clean it off the top area real good and use compressed air if available prior to removing the ring. After you replace the pump, be sure to use a new O-ring gasket at the top and use grease to lube it, otherwise it may break when reinstalling the ring. Be sure to use the new section of hose that comes with your new pump and also install a new strainer. Buy a new AC-Delco fuel pump if you can find one. Reinstall in the reverse order. And, remember to have a helper when doing this job (lol - see my last picture).
Good luck, Ed www.edgesz28.com