The top bit you are talking about is a vent do not try and remove it, follow the torque to the letter or you will be posting on how to get the busted bolt out
It is important to note as per Dave's post above that the torque value for the drain plug is only 15NM which is only 11 ft/lbs. Very easy to snap this screw!
Since it inly takes a very little amount of oil I use some more to flush out the last bit of dirty old oil. Also, grease the splines if you have the time!
The best synthetic you can get, as there is not a great deal of it in there and the specified change interval is quite lengthy. many change it much more frequently as it gives a chance to inspect the old for dirt/metal wear etc. considering the $2000 cost of a new one.