Put standard engine oil on the threads of the injectors. One injector at a time, place the threads of the injectors against the threads of the injector ports and twist the injectors into place by hand. The injector ports are located on the top of the engine block. Once the injectors are partially threaded into the ports, put a socket wrench over the injectors and screw them in snugly, then tighten them another quarter turn.
Put the threaded noses of the seating nuts attached to the ends of the injector lines into the threaded holes of the injectors. Twist them tight by hand, then twist the nuts another quarter turn with a wrench. Start the tractor and let it idle for 30 seconds or until the engine dies. It may die because of air in the fuel injector lines.
Bleed the injector lines. Loosen the nut on the top of the injectors with a wrench by rotating each one one-eighth of a turn counterclockwise. Pull up on the line to unseat the seal between the injector lines and the fuel injectors. Start the tractor again and allow it to idle until diesel squirts from the top of each injector. Re-tighten the nuts as the engine idles.