In this tutorial, we learn how to change your differential oil on a Jeep Grand Cherokee. First, you will need to remove the drain plug from the underneath of the vehicle, then let it drain out onto an oil pan, use a pipe and pump to do this. Once it's finished draining, you will need to replace the plug. After this, grab a new pump and pour your new oil into the pump. Remove the plug again, then pump the oil back into the engine. Once the oil is full, you can replace the drain plug and check the make sure the fill line is full. Drive the car and you're finished!