I have a 2006 V8 and the fluid path through the radiator is upward. Tried it the other way and ATF hit the fan. The tranny pump works like a check valve and no fluid can be forced the other direction. It just goes everywhere when the hoses blow apart. The time to change fluid would have been cut in half if I had the flow direction correct.
This should make it clear:
Used ramps to elevate the front and got almost 4 qts from the pan drain.
Definitely get new crush washers for the drain and inspection plugs. The originals were flattened too much to be reused. Cost me about $3.50 each at the stealership. You can get 10 for $13 on fleabay. I wanted to knock this out and didn't want to wait another week.
Never removed the fill plug and filled as shown in the pic. Used about 1/4 qt more than came out.
Next time I'll use the Valvoline MaxLife Synth from Walmart. Cost $110 for 12 qts of WS this time. Used 11 1/4 qts.