More like changing your engine oil than your Automatic Transmission.
I drive around to simple warm up the tranny fluid. I put the car on stands and ensure it's fairly level. There are two plugs that you remove with a large allen socket. I forget which size, I believe larger that 15mm,
I remove the lower plug first to control the flow a bit better. Place a collection pan and remove the plug. I use a magnetic plug, I forget it this is standard or something I picked up. Once all the fluid is drained, I remove the top plug and replace the lower plug with a fresh crush washer. I use a hand pump to fill the tranny . Full is level with the bottom threads of the level tranny. Once full, replace the top plug with a new crush washer.
I'll look up the torque values for tightening the plugs in the AM. Also you can search for an online Bentley manual and bookmark it.
Good luck Michael!