I've heard the Japanese license change test is difficult, what can I do to increase my chances of passing?

Six months ago, I, like many of you in Okinawa, was in a position where I needed to change my American drivers license into a Japanese license. I'd searched on the internet and talked to many people, and it looked like this driving test was no joke. Needless to say, I was worried, and being the impatient type, I wanted to get my license changed over ASAP. I went into the test ready to fail, but after I'd completed the course, the tester looked at my and said you pass with a perfect score. Was I born under a lucky star? I'm not sure, but I'd like to tell you what I did to pass the driving test on the first try.