Always use the ear muffs as has been said.
But you don't need to run that engine to change the motor oil- the oil for this motor is nowhere near as think as on a diesel.
Look up the manual online and you'll see that the starboard side of the shaft (for lack of a better term- it's the section between the motor and cavitation plate) is just a plastic cover and will pop off after removing 4-5 Allen head screws. There you will find the drain plug. I drain the oil from here every year without running the motor no problem. Turn the motor over to starboard a little bit so the drain hole is pointing down, have a bucket ready and watch it pour.
Bonus points- on my F200 (same vintage as yours) the oil filter is mounted horizontally- before draining the oil, tilt the motor all the way down, if you have enough ground clearance this will tilt the oil filter upside down just enough to drain, making the change out a much cleaner process (take 3 guesses how I figured that out).