Oil Drainage

It's the first time that I am doing some routine maintenance on my Yamaha F150 4-stroke (2003 model). Changing the gearbox oil was no problem. Can anyone give me some advice as to where the drain plug for the engine oil sits ? Do I need to remove the gearbox to get to the drain plug ?

[boats.net]

The drain plug is on back of mid section.
F150oilChange.JPG

Thanks, that is very helpfull.

drain plug

What size socket is that drain plug?

[boats.net]

14MM socket

thanks alot