Coolant is a little funner to change. On my VMAX 700 the drain is one of the bolts on the front of the water pump under the exhaust manifold. I had to remove the exhaust and I think I had the manifold off also. I found that you cannot get any sort of pan in there to catch the fluid, but I was able to get a plastic bag in there. I managed to catch most of the fluid in the bag and transfer it to a bucket. I say most, because of course the bag got snagged on a bolt and ripped a hole in it as I was removing it.
Drain it with the sled on the ground first, remove the fill cap to allow the engine to drain. Then you need to remove the seat, Lift the rear of the sled, and remove the plug at the rear heat exchanger. Make sure you have something to catch the fluid that will drain out of the exchangers. Once you remove that plug it will start to flow.