for the tranny crawl under the car and on the bottom of the transmission there should be a drain plug. looks just like the oil drain plug. if you want the filter out you need to pull the whole pan which is like 15 small bolts. they say to pull a filter every 30k or so.

For the replacement fluid just go into a parts store and tell them you need some tranny fluid. they can pull up your capacity on the computer and tell you how much you need.