Drew and stock49-
Thank you for the tips; I was able to remove the spring and hinge as a unit using a safety wire to keep the spring slightly compressed. The spring is about 14" long and the inner shaft thru the spring is 12", so some compression is needed.
Now that the assembly is out, I can do the repair to the end spring plate and install a new 5/16" rod.
Q: Am I correct thinking that the spring assembly is in a "relaxed" position during installation?
Stock49 it sounds like you have been down this road before. Thanks very much for the help.

Apache59