I took some pictures when I took mine off last year. There might be some steps missing, and I'm doing this from memory - but here goes!
Step 1
Remove the grab rails, take out the rubber covers and remove the bolts
Step 2.
Take off the seat (should start by doing that I suppose!).
Remove the plastic cover from the rear rack
Step 3.
Remove the tail piece. First take off the cable ties (circled) and unplug (there is a picture further on that shows these plugs) the lights and indicators.
Take out the four screws as shown.
The tail piece comes away.
Step 4.
You are now ready to fit the rails.
They fit here:
Using these bolts holes at the front (the light conectors are circled)
On the right hand side you have to pull out the elecectrical bits to get to the bolt.
The rear bolts are here:
As you can see they get alot of corrosion up there.
Finally, the lower mount. It just bolts into place. The Yamaha bolts are a bit weak, when I removed them one snapped (again corrosion on the bolts). You'd be better off replacing with a Stainless Steel set, as I did when I sold them.
Hope this helps a bit.