How to change the oil on a Mazda CX-5?

The principals of changing any fluid, including engine oil, in cars hasn't really changed in the last 70 years. Warm up engine, remove filler cap, drain old oil into a pan, swap oil filters, refill oil to recommended level using the oil grade recommended by the manufacturer. However, if you get something wrong in that process there is a real risk of injury or causing (financially) catastrophic damage to your car, so I'd suggest newbies take their cars back to the dealership, or a good independent mechanic, to have a professional do the job for you. They can also give your car a once-over to ensure nothing else needs repairing, or will wear out soon!