To replace the engine oil and replace the oil filter on a Kia Optima III, you will have to lift the front of the car. Then take off the cover with motor protector and unscrew the oil filter. Next, unscrew the drain plug and pour out the old oil. Once all the oil is spilled it is twisted the Cork. Then pour new oil into the oil filter. Fasten the filter in place. Then close the cover. After all these steps, open the hood and take off the lid and pour the new oil. Don't forget to check the oil level with the dipstick. For illustration purposes, all your actions are watching video on replacing the oil and oil filter on a Kia Optima III K5.