I have been looking at steps online on how to drain the coolant for replacement on my 2018 Vstrom 1000. The service manual I saw said to remove the drain plug on the water pump and then take off the radiator cap. On my wife's 650 Vstrom there is definitely a bolt but on mine, I only see a black plug there that does not look like a bolt. Here is a picture of what I mean with a red arrow pointing to it.