Is the fuel pump for the f250 6.0 diesel in the tank? Should I change the filters first before th pump or change all at once. Truck is driven about 6-10 times a year no more than 100 miles per trip. Should I be taking extra precautions on storage, fuel is almost always topped off.

Fuel pump and one fuel filter are on the frame, located on the driver's side. The other fuel filter is located on the engine (check for a water purge valve, too). Be sure to only use Motorcraft fuel filters, since aftermarket filters can adversely affect fuel pressure. I would change everything out at once, if the fuel pump is bad. Ford recommends changing fuel filters every 15,000 miles. In your situation, you might want to do it every 2 years. Try to run it more to prevent microbial contamination.

You may find this link of interest:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281