With the water grindstone but that is really very simple and fast and the knives are super sharp again. It takes some practice to really is really good. That's why I do not recommend the same to start with the best knives !!!
In retrospect, I wonder why I have not been much earlier made himself and sharpen my knife now even like. Because of the success is not long in coming and it keeps for a short time, felt a razor in his hand. Good knife vorrausgesetzt.