2002 Sportaxx 90 - oil change info

Hi I acquired one of these and plan to take it out with a group of us camping this weekend. I warmed it up and pulled the dipstick and the oil looks dirty. I did not get the owners manual. Can anyone tell me how much oil needed for an oil and filter change? How about reading the dipstick level? On my YZF 450 I warm it up, pull the stick and just drop it back without screwing it in to check to the oil level on the dipstick. Is it the same for this quad?
Thank you,
Steven