Just bought this Maxx with 93,000 miles after having SUV's for the last 20 years. I figure I should service the transmission since I don't know when it was last/or ever done. Any tricks to changing the filter? I know to loosen the bolts on one end of the pan and remove from the other to drain fluid or does it have a drain plug? How much fluid will it take with just a filter change? Can I use synthetic in it or DexIII or DEX IV?