That was me skylark, I unscrewed the screw, with a flat head screwdriver, and slid them out
When I tried to put them back, they kept upending
I tried all sorts including gripping with surgical instruments, but the rear ones would not stay up.
Infact it is not a problem,
I know where the seat needs to go, forwards and back
And being able to slide futher forwards and backwards gives the van much more usability beyond a camper
I could design a little grommet, that I could fit via the front gap,,,,,where you pull the plastic off to remove the seat altogether...it would have a hole in the middle for the screw, and hold the stop upright
But infact there is no need as we are functioning perfectly without it