1. If you're referring to the revision that allows you to use either film or digital radiographs, that hasn't been made available yet, as far as I know. You need to wait until that is announced, otherwise you'll be using the current version and will only be able to submit film radiographs.
Externship 2 Update 2016 - FAQ
Students can choose to wait until we have released the new Externship 2 paperwork with the updated skill sheets (no film x-ray requirements, dental x-ray requirements). If a student submits paperwork under REV1507 (currently available) they will need to do the film based radiographs.
There is paperwork that should be submitted after you have taken your proctored exams. The externship approval process does not begin until after you have completed your proctored exams and passed all the courses...
3. Externship 2 Preliminary Information (Practicum 2)
250 hours, 18 weeks
Hope that helps!