remove air from fuel lines? (7.3L PSD)

I have a 02 f-550 with a 7.3L Im new to diesels, so I'm going to need some help here. The truck was running fine, then all of a sudden, it was hardly running. Ford changed the fuel filter, and air filter, ran good. Now one month later, its doing it again. I got a fuel filter to do it myself. I took the old one out and the gunk build up inside the can was nasty. I think its rust from my tank. I cleaned it out, installed the new one. IT was hard to get started, but i got it. BUT, it runs just like it did b4 i installed the filter. I think theres air in the fuel line and i have no clue how to get it out. I looked all over google and cant find crap. And i how noowners book. Please help. Like i said, im new to diesels, so a step by step walk through would be great.