Ok, did some more work on this problem. Good news and bad news. I'll start with the bad. Being careful as possible to push/pry that rod/bushing out of the hole, following all the good advice offered above, oops, cracked the black plastic ear plumb off!! Damn!!! @Yosemite 's post above is right about this part, a questionable design at best I think I must have weakened it when I tried to remove it earlier in the week, before seeking advice here. Well, I gave it the old college try anyway. Worse case, I can always buy a new one.
The good news is I was able to repair the passenger door lock cylinder so now the same key that works all 4 locks. 2 of the wafers on the passenger door , one on each side, were sticking up quite a bit too high, preventing the cylinder from turning. My solution was to dremmel-grind those uppity wafers down to size to match the others. Voila, key works now.
FYI, "Wafers" serve the same function as ordinary house door lock "pin tumblers", but wafers are used in car locks for some reason. I don't have a theory how the wafers on the passenger side could get unaligned like that, since presumably the wafers were all the same dimensions in all four locks (two doors, ignition, and trunk) when the car was new and the key was new. But somehow over the years with the key wearing and unequal use of the locks, it happened. What I don't understand is why the seldom used lock is the one that failed, but the locks I use all the time are still working fine.
Next job, I started to repair the broken off plastic ear. The simple fix, super glue the broken part back on, that didn't take. So I JB Weld'ed and clamped a robust strip of sheet metal to the moving part of the arm, with an oval shaped hole drilled in it to fit the bushing. I think the oval shape will make it easier to insert the bushing via the bushing rotation method suggested by Tester above. JB Weld is now setting up. I'll give it a few days before testing it for enough holding strength to open the door latch.