I generally change mine every 50 hours.
Normal ATF unless the manufacturer recommends something else.
What I do to replace mine:
Items required, bucket, 3 empty quart bottles, hand pump, lot's of rags & large towel.
Put the towel down on the floor, I put the empty quart bottles in the bucket and pump out the old fluid into the empty bottles, replace with new ATF what you took out, test levels and you are good to go. I use the bucket to catch any fluids that might escape. Keeps the carpet clean.