What is the most efficient way to adjust the timing of my Audi A4's engine?

I have noticed that my Audi A4's engine is not running as smoothly as it used to. I suspect that the timing may need to be adjusted. What is the correct way to do this and how often should it be done?

The best way to adjust the timing of your Audi A4's engine is by using a timing light. Start by locating the timing marks on the front of the engine and attach the timing light to the battery and spark plugs. Then, use the light to align the timing marks on the engine with the correct timing degree according to your manual. This should be done every 30,000 miles or if you notice any engine performance issues.