I have tried many, many times to make those levels, and ruined many, many cases in the attempts. In my experience, i cannot produce good-looking, even, or symmetrical chamfers with any type of dremel (I have tried 4 different models, with all manner of attachments) or a drill press.
I know its not what you want to hear, but the truth of the matter is that it takes an experienced craftsman, using professional precision tools, to cut those chamfers and make them come out right.
I have had marginal success with using needle files and sandpaper (120 grit all the way up to 3000), on a small scale, but I finally had to accept the fact that cutting bevels requires more skill than I possess. Its frustrating and it sucks, but maybe you can save yourself some money, time, and frustration by finding a modder who can do it for you.
Ive heard that a lapping machine is the way to go, but never used one personally.
When it comes to chamfers/levels, we all pray at the alter of Dbane. Rolex itself can't do it better than him.