I spent the better part of an hour today
arguing with the nut to the far left here in the picture. I wanted it
to break free and turn freely, but it kept its arms crossed and
insisted on not budging.
The main problem was the lack of leverage. The nut is at the end of the
positive side of the flow and the fact that it wasn't stationary made
the job that much more difficult. After much inner debate I decided to
relent and let the nut stay where it was. I then squashed what was left
of its precious copper connector and bent it in a way so as to fit
snugly in the slot where the bitter end of a thick wire would go in the
new connector. Once tightened down the new configuration seems solid
enough to last another 250 thousand miles.