The preparation for the exam is demanding, but the result will definitely be worth the effort. The choice of a competent instructor, with the necessary certifications, is also very important in order for the student to fully grasp the methodology components, pass the exam, and to implement the knowledge acquired in real projects.
Take the exam relatively soon after completing your studying/preparation. Fresh memory helps given there is terminology and contents that one needs to remember. Other than that, it should be very feasible to pass the exam if you study all components of the methodology well (e.g. roles, definitions, templates/documents contents, phases etc.)