Hi Sven!
I did the exam a few weeks ago and, fortunately I've passed.
All the advices given by Michelle helped me a lot, but I believe the most important thing is that I did the Visual Analytics Fast Track and used the materials of the course for my preparation.
You don´t need to take all the course again, there 3 main areas that you must know:
1 - Data Builder
2 - Data Explorer
3 - Data Designer
You don´t need to study the administration of the tool. I suggest, if it is possible, to take the course, and then review those three areas and I believe you can pass the exam.
Good luck!