its simple. if i can do it you can. just change the oil filter... put a towel under it and remove it and replace a new one. dont worry oil wont pour out of the hole. only oil you have to worry about spilling is whatever is in the filter itself. hook up a water hose to your cooling system and let your ski run. i bought a 2 dollar oil sucker from harbor freight just suck up what oil you can and replace it with new oil. keep doing this until your oil is clear. i think it took me about 5 or 6 quarts until i felt comfortable with the condition of the oil. make sure not to fill it up with too much oil. make all oil measurements when oil is warm