I realize this does not help with the numbers explanation, but it might help with the perspective on why the numbers may or may not be of importance, depending on the situation. If you want to know how to alter your numbers pretty easily with diet, watch a bunch of Dave Feldman videos on Youtube. He shows how you can eat a terrible diet and purposely lower your cholesterol numbers (might be helpful if a person needs to apply for life insurance of something like that). Lower them a whole lot more that statins do, and over a very short period of time.
Edit: another interview style. https://www.youtube.com/watch?v=3iikmSfbQJY "American Nutritional Society four years ago said cholesterol is no longer a nutrient of concern". So why are so many people still afraid of cholesterol? The word has not got out very well.