I just changed my entire cooling system this afternoon. It took a little under 5 hours. I wanted to add a note about the automatic transmission thermostat. To remove the old piece, pull up on the black cylinder. It'll pull straight up and out. The plastic is very brittle and may take some effort. The new thermostat just gets pushed straight down. There is a guide tab that faces the front of the car.
Also, I accessed the engine block coolant drain plug using a small 1/4" ratchet. It was a pain and made a mess.