Hi Arne,
My best advise with learning new choreography is this, first play and observe the DVD to know the music then do it with the DVD at least 2-3 times. then play the music over and over in your car, at home, on your ipod etc. if it is too much to learn all 10 tracks at once do three at a time,. That playing over and over again thing really assists the moves to sinks in and if you are unsure you go back and re watch that track on the DVD again to make sure. I think knowing the choreo is the most important then you can feel relaxed in your teaching as you do not have to focus on anything but the class in front of you. i teach it to the cat the kids or any one at home before teaching it to the class
all the best
Liza