You apply any way you like, usually through a recruiter or on their website. The very first step is a written test. The test is pretty long for the time you have but if you're well prepared it's fine. Then if you pass the test you get through to the first round of interview, which was one on one for my part. Some friends of mine went further in the rounds but I don't know anyone who actually got through. It's a very difficult process because they are extremely picky but if you like brain teasers and interesting interviewers, it's definitely worth a shot.