Race-tech kit on the front forks.
Fox Shock in rear.
Slip-on can(s) for teh exhaust.
'Factory' brand stage-1 jet kit.
K&N airfilter (stage-1)
Fender elimination (rear)
After all that youd have a pretty healthy setup on that 500R.
I really dont know what else you could do though, without doing an engine teardown and serious internal engine work ($$$).