It fairly hard to get to - located in the Y where the two exhaust pipes come together in about the center of the car. You really need a special tool - an open socket of that size. I had never seen one before - it's like a 300 degrees socket with an opening on the side of the socket to slip on from the side. I was fortunately able to borrow one from a mechanic and the job then became quite doable - put clearly the tool was the key. My recollection is that I had to raise just one wheel, the left front, on a jackstand.