Just did an atf fluid drain and fill on a 2014 santa fe a few days ago.
There are tons of videos online of people doing it, but I don't think they are doing it the way Hyundai intended it to be done: http://www.hsfmanual.com/fluid_repair_procedures-273.html
The Kia sorento video posted here is pretty good, but while reading some forums i noticed the some people who followed his method has some issues. If you leave the fluid level port open while filling, some people had it start leaking out after 2 liters were poured in. Draining the transmission gets out about 4 liters of fluid, so you should be getting a lot more than 2 liters back in there.
How i did it:
** The car needs to be level for this procedure. Keep this in mind if your using ramps or jack stands.
1. Drain the atf from the bottom of the tranny. I Got about 4 liters
2. On top of the transmission there is a fill bolt, I filled in about 5 liters through that hole. It also vents air through that hole, you have to fill slowly or it will burp it back up and you will make a mess.
3. Turn the car on and let the atf get up to 50-60c. I used an infrared thermometer to roughly determine when its at that temperature. I also let it heat up at idle, which took a while.
4. Shift the car from park to drive and then back to park. Stopping at each position for 3 seconds. Do this twice.
5. With the car RUNNING and in park. Open the fluid level port and let the fluid drain until it becomes a thin steady stream
Here is a pretty good video i found of this being done on a Kia soulhttps://www.youtube.com/watch?v=6cUUniBpMgk