With regards to the topics on Part I, my opinion is that it's best to read the theory portions, certainly, of the books for those things on which you have a lack of experience. It might help to understand them from the level of the developer in some cases (such as
EJB), but bear in mind that the exam more covers the theoretical application of the technology, and the aspects such as security planning and scalability, none of which will be covered in the first chapter of a book.
For Part II, there's no real way to 'study'. It's a matter of knowing how to do it, more than what to do, and here's where a novice at UML is going to get tripped up. This isn't all you're going to need to know - you also need to know, for practical reasons, where to apply the
Java EE 5 technologies and how to do so - but without practical experience in design, you're going to be sunk. Part III builds on this, by asking you the why's of where you applied the Java EE 5 technologies, so....