ITAP Thoughts

I'm wondering how much time I should spend preparing for the ITAP tryouts. There were about 60 people who attended the mandatory info session. Not all who were present signed up to tryout. There are two rounds of elimination and then an interview. I hear they ultimately take around 20 people. The first round consists of being prepared to make a closing argument for both the People and the Defendant. The second round is a bit more work having to deal with direct examination of a witness and a cross examination of a witness. So knowing all that... how many of the 60 people would they cut after the first round of elimination and how much effort do I have to put in to be one of them? My tryout is Tuesday night, someone give me an answer well in advance.