Need, DIY differential gear oil change procedure / instructions. The differential case is "covered" with hex bolt heads of the same type. I can't find any that have a visible sign that they may be anything but fasteners as opposed to fill of drain port plugs. Have spent hours searching the internet for a clue. It's as if a 2016 Camry doesn't have a differential at all. Could it be that the only way to drain and refill the differential it is to take it apart?