Volvo Penta 3855694 How Do I Change The Oil In My Volvo Penta 270 Stern Drive?

How do I change the oil in my volvo penta 270 stern drive? - volvo penta 3855694

AQ125A 270 Volvo Penta stern. Controlling the oil plug came loose and I had water in oil. Is there something special that I have when an oil change?
What is the best oil / lubricant the device in operation?
how much oil it holds the city?