Triumph Tiger Sport - Bodywork Screws, How To Get Out!

Hi all

On my Triumph Tiger Sport bodywork, the bit that surrounds the silencer bracket, seems to be held in with what look like small black self-tapping screws into a sort of rawlplug type affair. Either the rawlplug turns with the screw, or if I get long nose pliers onto it, the screw turns but does not come undone. Am I missing something? Is the there a technique? - Thanks