Looking at it and thinking about 20 years back…..
Let the trailer down, let the neck relax, pull shims out of the back, winch neck up so front blocks are loose, remove them, winch neck back up into 5th wheel, block under neck, back up, air up (assuming air ride), hooks near front of neck should clear horizontal pins and you can pull away.
If no air ride those older trailers had some rigging in the neck where you could use the winch to lift neck after you backed up enough for hooks to clear pins. It’s a chore. Done frequently you’d get fairly proficient. It’s been a few years since I messed with those and the old folding necks operated via a winch.