The Yamaha TTR 230 is an off-road motorcycle, so it does not use a steering wheel or buttons for operations such as changing the engine oil. If you want a detailed guide on how to change the engine oil for this motorcycle, I will provide it for you: To change the engine oil of a Yamaha TTR 230, start by putting the motorcycle on a stable stand to keep it upright. Make sure the engine is warm, but not too hot, to facilitate oil drainage. Under the engine, locate the oil drain plug and place a container to collect the used oil. Use a wrench to unscrew the drain plug and let the oil drain completely. Also remove the oil filter, which is usually located on the side of the engine, and replace it with a new one. Apply a thin layer of fresh oil on the gasket of the new filter before installing it. Put the drain plug back in place, screwing it tightly. Then, locate the oil fill plug on the top side of the engine and pour in the new oil, using the quantity and type specified in the owner's manual. Finally, start the engine for a few minutes and check for any leaks. Turn off the motorcycle, wait a few minutes, and check the oil level with the dipstick or indicator cap, adding more oil if necessary. The process is complete!