To change synthetic oil, drain the old oil out of the engine, replace the oil filter, and refill the engine with new oil. This is an easy piece of self maintenance to do at home, according to HowStuffWorks.
The first step in changing a car's oil is to drive the car for a short time so that the engine and oil have a chance to warm up, according to HowStuffWorks. Once the engine has warmed up, park the car so that it is on a flat surface. Place an oil pan under the plug and then use a socket wrench to unscrew the nut, allowing it to simply fall into the pan when it comes loose. Let the oil drain out over the next few minutes.
Once the old oil has drained out, remove the old oil filter, minding the hot oil inside of it, and replace it with a new filter, advises HowStuffWorks. Rub a small amount of oil on the new filter's gasket before installing it, and screw it into place until it is snug, but do not over-tighten it. Then, replace the oil drain plug, and fill the engine with the appropriate amount of new synthetic oil.