Kiesler pillion seat cover/cowling

I am trying to register my scooter here in Australia as a single seater as i am the only person who rides it.
if i purchase the kiesler pillion seat cover for my aprilia sr50 2008 can i remove the seat and replace it with the cover or is it not that simple, Do i need to buy the underseat as well how do i go about changing my scooter to a single seat
Any input would be appreciated