Dexron
For a complete fluid exchange you disconnect the cooling lines.
One is the "in line" to the trans and the other is the "out line" to the cooler.
Just need a few of feet of the proper sized rubber fuel line. Just measure what you will need.
Add the rubber lines to the ends of metal ones, long enough to put one in a bucket of clean fluid and the out line into an empty bucket.
Start it up and put it in neutral so the pump is working. Let it run until new fluid is coming out of the "out line".
Re-attach the trans lines and fill to the proper level using your FSM for the correct procedure> Very important to follow the Manual.