The metal floor on your bed needs replacement? This is the first I've read that this has to be done on an 04 to 08 F150. Were you hauling salt?
To remove the bed, you'd need to disconnect the factory wiring connections to the taillight and license plate lights, then remove the 4 bolts that hold the bed to the frame. And a few buddies to lift it off.
Give an answer, they learn for the day; suggest a search, they learn for a lifetime.
2005 F150 STX Regular Cab (4.2 liter V6)