The complicated part comes from putting the gun back together. The Hammer and lifter are on the same screw and the hammer is under the stress of a coiled main spring on a plunger that goes from a stud screw on the lower tang to the base the the hammer. In order to put it all together you need to compress the coil spring and put it in place. A long time ago (1960s) my gunsmith solved the problem by drilling a small hole in the plunger shaft inserting a probe and winding the spring up against the probe. He could then put the assembly in place and pull out the probe. Another problem area is the two part firing pin. The mating surface between the pin in the frame and the rear of the pin in the bolt get worn down to where they do not transfer enough energy to fire the primer.
