Hi Kathleen! The legs can be cut with a hacksaw and new nail-in pads or feet can be installed on the bottom. Determine the new length of the legs, and wrap masking tape around the leg at the new length to create a straight line then cut with the saw. Install the feet on the bottom... I hope this helps!
Best way to get the legs level is to find the height that you want and cut a small piece of wood to that exact height. Place it next to the leg and swing it around as you mark the piece all around with a pencil. Do on each leg and cut precisely on the line. Your bar stool will stay level.
here is info. for you https://www.google.com/search?q=How+do+I+shorten+a+bar+stool+with+rounded+legs%3F&rlz=1C1CHBF_enUS750US750&oq=How+do+I+shorten+a+bar+stool+with+rounded+legs%3F&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8