The bottom panel is kept in place by 10 flanged screws. After I secure the car once lifted on jack stands, it took only 5-10 minutes to remove the bottom panel. Be careful when you remove it - has lots of sand and pebbles. I washed with a hose for a while. I got almost one pound of sand and stones out of it.
The drain plug is red made of plastic (acetal I believe) which has 2 o-rings. The dealer said they need not to be changed first time - but later on. The drain plug can be unscrewed by hand. It is located on the driver side of the car. It takes about 10 minutes or so to fully drain. To make sure that it fully drains make sure the filler cap is removed (it is near the air filter on the passenger side of the car). Good luck.