I recently bought ES350 2010 at 90 K miles. I decided to do AT flush. Here what I did for my Lexus

Transmission fluid: Maxlife Valvolin WS ( 4 jugs of 1 USA Gallon, used 3.5 jugs)
AT filter and gasket from NAPA
Now 200 miles since I flushed it no issue and no leakage.

Tools:

• 6 mm hex head socket
• 10 mm socket
• 24 mm 6 point socket
• 2 foot extension
• Level meter
• 3/8 inch viny tube. Bought it from Lowes. In the plumbing/land scaping section, they have cut pieces which I found enough
• Temperature reader

Torque:

• Pan hold bolt 66 lb
• Drain plug 30 lbs
• Fill bolt-on side 36 lbs

Process:
1) Drained through the drain plug and dropped AT pan
2) change filter, cleaned magnet and pan followed by installing the pan
3) Disconnected incoming/return AT line from the cooler and used the clear tube to divert to a graduated jug
4) Filled AT through the fill port ( 4 Q )
5) Started the engine till 1 Q out
6) Filled with 2 Q through the fill port and started the engine till 2 Q out
7) Repeated 2 Q out and 2 Q in till I see clear fluid coming out.
8) I made sure during the whole time I have 4 Q in the pan ( you need to count how much out and add that much in. )
9) Started engine and keep it running till it reached 104 F
10) Removed the drain plug and put it back when I noticed fluid thin stream just before it changes to a continuous drops

'Key Points: Level the car. You do not need to jack the whole car just take out the driver's side wheel and use a tool to check the level. I used an infrared temp gun and pointed to the AT pan. One of the AT pan screws was at a difficult position I used a small wrench, see the image.
Also, make sure you can open the fill plug first before starting all this. If you can not you will end up AT with no fluid as you can not fill the lost fluid. So make sure you can open the fill plug

This video helped me

 

 

Sounds and looks great. There is a more detailed post somewhere in here