Rubber rear fender thingy

[HUNTS]

I assume that this black rubber grommet thingy is for different seats when they are fitted? Does it just pull out from the top of the guard or is it a major operation to undo covers from underneath? Is it a screw thread under it?
I just don’t want to cause unnecessary damage.

 

[skidward]

It's a plug for the pillion seat attachment. The one I have pops right out.

 

[skidward]

 

[HUNTS]

Thank you everyone
I’m removing the rubber thingy and putting either a round metal Australian or German flag in its place. Both are the same size as the thingy.