Dinette drop down

[gmcfarla]

Hi, can anyone advise how to drop down the dinette on the cruising version of the Mk 3, the screw realeass the leg but we can’t work out how the attachment on the interior of the hull (?) works. There seems to be a button to push to allow release but it doesn’t seem to work.. is there a trick to this? We assume it is meant to unhook and drop down to extend the quarter berth.