I didn't find very many good pictures on how these things are assembled. I finally got them back together with a coat of graphite and new roll pins. I think I was missing a pin and the previous owner had put the handle on upside-down so it interfered with the tailgate when the latch was down. Anyway, here are some pictures of the units assembled, and how to get them into the access holes.
Installed - you can start the removal by tapping out the inner-most roll pin. This unlocks the pushrod. Once it's out you can remove the spring and latch assembly from the carrier.
Here's the assembly:
Then you can unscrew the carrier and wiggle it into place to remove it
Here's the sequence to pull it out; reverse to install.
Here's the cam and latch in the middle.
Line it up like this to get the handle straight and the pushrods in the right place for when you assemble it. The handle points to the passenger side when it goes in the truck.