If shooting one in that kind of terrain coming down from a ridge at binocular distance was the plan then it must be a solidly planned operation to guarantee securing the body. One would be keeping a sharp eye on the kill site and sending a drone to over fly the scene and get the GPS coordinates of the body while at the same time keeping an eye on it so it doesn't disappear. Then the team- with the GPS coordinates- takes off to retrieve the specimen while the spotter and drone pilot maintain vigilance. This is to report to the team the presence of any other creatures that may show up in the area for whatever reason. If they take the body the drone can hopefully follow their route. But the team needs to be equipped for the terrain as far as extracting the body and or dealing with other individuals that may show up.
In all cases the exercise will neither be easy nor lack danger. And that is only the beginning.........because after securing the specimen, then what? Any plan needs to be fully thought out from beginning to end which would include delivery of the body to a trusted facility for research. That facility shuld be set up in advance so that it can be prepared to conduct the study without delay and not just place the creature in a queue to be studied later. Because as you say, Norseman, it would be one of the greatest discoveries of mankind.