68 Barracuda fastback Rear Centre

So I need to get to the rubber around my fuel filler tube but its under the centre section of floor in the back...The manual shows me nothing...is this panel just screwed down under the carpet or something? Or do I need to remove the side panel to get this up for access??
It's just screwed down remove the rear seat you will see the screws. There are more screws in the trunk by the hinge I believe.