First posted as a comment
It looks very much like a lightweight hiking chair I own. Is there not sufficient give in it to lift one of the outer 'pockets' away from the rod? Each one should get easier after the first.

I found the manual - apparently it's the other way round, get the rod out of the socket in the centre first, before releasing from the pocket. Sounds like some effort may be required - as indeed applies to my chair too.

Presumably, disassembly is the reverse of assembly...

& from my chair…

Assembling your Helinox chair is quick and easy. The shock-corded frame will virtually self-assemble – just be sure all the poles are fully inserted into the hubs. Always fit the seat to the upper rear poles first. Then, lay the chair on its back and use your body weight to flex the lower seat poles into the last two pockets. Brand new seats can be a little tight and the durable fabric helps prevent the seat from sagging over time. But don't worry, the more you use your chairs, the easier they'll be to assemble.

You do have to get your back into it a bit to start with - it's part force, part technique ;)