1) Remove the under body shield on the oil pan side , bunch of torx heads and a few plastic clips.
2) The drain plug faces the ground, uses a torx bit I believe. Remove and drain.
3) Measure the fluid you got out, should be around 700 ml. Probably will be metallic looking from wear.
4) Clean the drain plug, should be some metal on the magnetic end of it. Re-install (2015 Torque spec is 33 lb.ft)
4) The fill plug is directly under the rear turbo, same style as the drain plug (See 1004Ron's post).
5) Grab some 75W-140 gear oil, I recommend AMSOIL Severe Gear, or Motorcraft. 1 bottle per flush you plan on doing.
6) Fill with a hand pump, roughly 650 ml, at about 700 ml the fluid will start to spill out of the fill port. Total fill capacity is 700 ml.
7) After you get the roughly 700 ml in and it stops dripping, put the plug back in, clean any metal off the magnet. (2015 Torque spec is 33 lb.ft)
8) Re-install the under-body shield.
9) Drive it and then check for leaks, if you plan on doing multiple flushes drive enough to heat up the oil.
The oil that comes out smells horrible, so enjoy!
Depending on your mileage you might also want to get an oil analysis done. OAI Testing is pretty good.