A low cholesterol diet is a good start. No red meat except liver, cut down on dairy, skimmed or semiskimmed milk..... Replacing fats in the diet with those high in mono and polyunsaturates helps, as does eating lots of soluble fibre (present in whole grains. Porridge is an excellent source). If you try this you should see a difference in ldl levels. But if not (and some people do seem to be able to manufacture ldl's) there are various drugs prescribable to lower cholesterol.