Thanks for wonderful guide and pictures, it made me do a flush much more comfortable. Instead simply drain and fill, I went with filter, and gasket and removed pan after seeing your tutorial.
All went well, but few things I might want to add as tips are:
1. Drain plugs need 5mm allen wrench (or equivalent hex bit).
2. 17 mm open spanner for fill plug
Torque for Transmission Pan bolts is 7lb-ft only.
So do not over tighten. Initially I tried my mid range torque wrench which start at 5lb-ft, but I felt it is not accurate at such a low range as it taking more torque than I was expecting. I picked smaller one and use 84in-lb, which turned out good idea.
If you are using jack/ramp like me without access to lifts, make sure car is level.
I used ramps in the front and jack stands in the rear. But it was tilted little bit Ramp height was not enough.
So I had to put jack under engine and lift it little bit to level front to back. Other wise your fill level may be incorrect.
Also check level side to side also. I observed it was little bit titled to passenger side, so before filling I leveled with jack. So leveling is very important, otherwise you may under-fill or overfill the transmission.
I did one silly mistake. I filled while engine running, and made sure transmission temp is between 30-50C. (when I started draining it was around 44c and by the time I completed filling, it was around 34C).
By the time I filled, exhaust got hot, and without thinking I turned off engine, forgetting oil will come out of fill hole. Oil started pouring down, then I started right away and closed the plug.
I ended up losing about a quart, so had to go and get a quart, fill it while engine running. Total I filled about 5.8qt. But just drain and fill also should accept about 5qt if leveled correctly. last remaining will not drain because drain hole is higher than bottom of the transmission pan.
I also had a "tap" like iflyjetzzz had it on first start. But on subsequent starts it is gone. I am guessing it is air in the system, and once air is out, it is good.
My car has 105k miles, and always shifted perfect, and it is shifting same way. I have not noticed any change, for better or worse!
To my surprise, drained oil is in better condition than I expected. Though it is darker it still has red tinge to it, and good feel to it. Better than 60k oil (supposed lifetime oil) from my Prius transmission recently.
Thanks all great for great contribution!