How to remove poptop headliner

[Rowe181]

Hi all I need to remove the ply board that’s attached to poptop (austop) fibreglass roof. Before I mangle any more of these fixings does anyone know how to properly remove these?

 

[Grim Reaper]

Flat screwdriver between the centre part and outer part, twist to lift the centre up, then reposition the screwdriver to beneath the outer part and twist to lever it out, A trim tool can be used as well.

 

[Rowe181]

Thanks got there in the end!