I just had to buy a fuel pump and sender not long ago because my hanger / sending unit was rusted out. If your hanger is still in good condition then you can just buy the pump by itself which is only around $100 at O'Reillys.
I checked Autozone but I dont believe they sell it without the hanger.
The easiest way to change it out and they way I did it was to cut a hole in the floor of the truck, if you have a 4 door this hole will be right under the rear seat behind the driver. What you do is go under the truck and drill some small holes with a drill to mark how big the hole will need to be, so drill one hole in each corner of where your hole will need to be. Then put a wet towel on top of the fuel tank, now from inside the truck you can use a 4" grinder with a cutoff wheel and cut out your hole.
To seal everything back up what you want to do is buy some aluminum tape and heavy duty gorilla tape with some black silicone. You use the aluminum tape around the edges of the panel you cut out because of it's strength and seal it from under neath with the silicone, then finalize it inside the truck with the gorilla tape.
Good luck