Over the years I have fixed sagging doors on 1970 Mustangs three times. Each time I did it slightly different.
The first was in the mid-70's and I went to the dealership and bought the whole assembly. The swap was easy but lining up the door was a PIA.
The next time was in the late-80’s and this time I took the hinge off and rebuilt it. Smooth job again until it came to getting the door lined up ... again.
The last time was a few years ago and this time I took a Dremel tool and cut the bottom of the pin off where the stake marks were. I knocked out the old pin and bushing with the new pin and into new bushings as I drove the new pin up into the holes from the bottom. Once in, I beveled the top to keep the pin from falling out even though the stake mark on the head of the pin fit well enough into the bushing it probably wasn’t required. I did install the bushings from the top so there was no fear of them falling out either.
While not concourse correct, it was much easier the last way and the door alignment was as right on as when it left the factory when I was closed the door the first time.