How do you change an injector for a 350 mechanical motor mack?

To change an injector on a Mack 350 mechanical motor, first, ensure the engine is cool and disconnect the battery. Remove the injector lines and the hold-down bolts securing the injector. Carefully pull out the old injector, clean the seat, and then install the new injector with a new seal. Finally, reattach the hold-down bolts and injector lines, and reconnect the battery before starting the engine to check for leaks.