Ah, second biggest question of all!   First off, don't be nervous, we want you to succeed.  There are 3 types of testing; Mat Instructor, Reformer Instructor and Comprehensive Instructor.  Depending on which you want to be, you only take one test.  Once you are done with your coursework and hours, you submit them and an application to Balanced Body.  Upon approval, the final test consists of 50 to 75 multiple choice questions and a practical session of you teaching a student.  We go deeper into specifics during the modules, the important thing is to not stress too much!  Details of each set of completion requirements can be found here.