I've done it on my Xciting 500 which should be about the same. Take off front fairing. Take off side skirts, take off bottom plastic underneath engine area. Take off bottom radiator hose and let drain into pan. I even took off a small hose which runs under the engine and let that drain. Crank engine over a few seconds to pump out a little more of the old coolant. Cover or pour out the old stuff so any pets don't drink it - get sick or die.
Re-install hoses and tighten clamps. Fill with new NON-silicate antifreeze such as Prestone 50/50. Be very careful to read ingredients on what you buy. I think if it says contains silicate inhibitors it's not for our scoots. You're not done yet so don't put the fairing back on. You must now get all air pockets out of the system. People approach this in different ways but here's what I did. Run engine with radiator cap loose and look under cap every minute or so and you start to see air bubbling out. That's good, let it do so untill fluid gets hot and expands so much that it starts to overflow. Stop engine and let cool preferrably 45 minutes or more. When it's cool, there will be room to add more fluid. Repeat the above. Several times if necessary or untill you're pretty sure there's no more air in system.
I left fairing off and rode around yard at this point for a good long while, like 30 minutes - let cool again and check when cool to see if fluid is needed to bring it up to the cap. All necessary since if you leave any air in there your temp will fluctuate next time you ride and have to take it all off again.
By the way, when draining, also take the hose off the overflow tank under the left floorboard and drain it. You can refill it when you refill the radiator.
