Hi XXXXXX
On the top of your fuel filter housing(the filter on the engine not the prefilter mounted in the boat) there is a air vent screw that can be loosen with a flat screwdriver. It will have to be unscrewed about 4 turns. A rag placed around the fuel filter housing will help catach the fuel that will come out. Then you can pump the air out of the system using the hand pump located on the fuel transfer pump. If the pump does not seem to work try turning the starter to get the pump mechanism to the low side of the cam lobe. Once good fuel is coming out of the air vent screw close the screw and loosen the injector lines at the injectors. With the throttle about half throttle crank the engine until you see fuel starting to spit out of the injector lines. Tighten each line as it starts to spit. When the engine starts shut it off and tighten the rest of the lines. Be careful around the injector lines with your hands as the fuel coming out can be at high pressure and can penetrate the skin. This is why you should stop cranking otr shut the motor off to tighten the lines. Once all the lines are tight start the engine and check for leaks. No leaks then you are done. Hope this helps.
Marine Mechanic
marine diesel technician for over 20 years.