On my Atlas FM Erie Built A-Unit rear truck, I cannot figure out how to remove the T-shaped coupler pivot, Part 687073 so that I can remove and replace the old coupler. I cannot rotate the rear truck far enough outward to allow dropping out this coupler pivot from its mounting hole in the rear truck. And it does NOT appear that the bottom end of the coupler pivot pin, onto which the E Clip, Part 680508 attaches to secure the remounted coupler into place, is threaded for its removal. So I'm lost regarding how to get this coupler pivot pin removed.
So how does one get that coupler pivot pin out of the truck mounting hole so that I can switch couplers?