Auto tranny drain plug

[Yawesh]

that's one flat looking plug - is it for draining the tranny fluid?

or do you have to remove the entire pan?(tedious task)

Also, after draining , how much new fluid should I put back in? (think the manual states 2.6 quarts that the tranny holds - How much generally gets retained? I'm thinking at least 1 quart....)

Thanks everyone, only manual tranny info on search!