The others have forgotten one very important step
Remember to pour coolant all over the driveway
I just did mine last week for my new rad hoses,used the manual to guide me through,just below the drain bolt was a cable clipped on,if i did it again id detach that cable as it got in the way of my little funnel,thats what im blaming for the mess i made anyway,it comes flying out at a surprising rate for such a small hole.
After id shaken the bike back & forth to get out as much as poss i then stuck the garden hose into the filler cap & flushed it through until it ran clear.
As already mentioned,top up as slowly as possible to stop air getting in,once the coolant is all the way up to the top then shake the bike back & forth,its surprising how much it'll keep dropping with this method,keep topping up then shaking & topping up again.
Get the tank back on,start her up,run for a few minutes,blip the throttle to about 1500 to 2000 revs a few times,switch off,allow to cool,lift tank & top up via filler cap again