Jay:
If memory serves me, I recall a fellow PSC owner having to cut access opening on the front face of the "base" on which the head sits to access the hardware and then later building a small access panel door to finish out the opening he had to cut...
....but as each year passes, "if memory serves me",
is becoming less reliable so I'd seek out the wisdom of the group here. I did a search to see if I could find that thread for ya, but no luck...
Good luck completing a tough project.