It took 60 days from me , from 2 to 4 hours daily.
Below the history :
1- Read "Head First Servlets and JSP, Second Edition.pdf" book two times , it is really great book.
2- Read Servlets 3.0 Spec (the new topics )
3- Servlet 3.0 from JPassion (70 Important pages for only the new features at 3.0)
4- Studied http://exam.piotrnowicki.com/viewQuestion.xhtml?q=Q01 , It's like servlet 3.0 and EE 6 tutorial , very good questions for revision
1- test-inside exam , it is very good , many questions from it come at the actual exam
2- Enthuware Test (It is really really great and helped my alout , many questions from it come at the actual exam)
Enthuware has 10 mock exams , i solved each one two times , it was very helpful