The drain plug is a two piece plug, you undo the entire plug to drain the fluid. Then you need the tool:
Amazon.com: OTC 6604 Transmission Fluid Fill Adapter: Automotive
this goes in the center of the drain plug (there is a hex key headed insert) and you have to pump the fluid UP into the transmission. Once it starts to drain back, put the center insert back in and start the car - run it through the gears and get the transmission up to temp.
Then - leave the car running, in gear, and put your OTC tool back in and pump more fluid up until it starts to drain back again.
It can be done on jack stands, but it isn't easy and not something you really want to do with a car running over top of you while you are trying to move around on your back with limited space. So if you don't have a lift available you are better off biting the bullet and having it done at the dealership (most transmission shops and oil change places can't do the sealed Ford 5R55 transmission).