I have attempted replacing the pins and bushings in some GM products, and
finally subbed the job out to a body shop.  I just didnt have the
wherewithall
to do the job easily.

For many GM products, the bushings wear out quickly,  especially if they are
not lubricated properly.

The biggest problem I found was removing and replacing the springs inside
the
hinges.

I got a body shop to do it for $35 per side.  Cheap.

The plastic sleeve insert in the bushing on my car disintegrated and I
relaced the whole upper hinge on the driverside on my 91 Bonneville a
few years back. Got a hinge off one from a junk yard car that had very
little wear. I got it installed & lined up pretty close myself, then
took it to a body shop for a final adjustment.

The door latch wasn't hitting the striker on the center post properly.
The striker on my car is non adjustable.

The body shop had these eight foot long pry bars and slide hammer and
one hell of a  sledge hammer to knock the hinge  back into alignment.

The guys at the body shop couldn't believe how close I got by using jus
two hands, then I told them - I didn't loosen the lower hinge when I
installed it, I sprung the door slightly out from the upper hinge, then
slid the replacement upper hinge in where I put a line up mark then
bolted it down.

Good Luck

harryface

Look through this group for a similar thread on GM door hinges over the past
few days.  You'll find a thread that explains the process.  In short - you
need to replace the hinge bushings.