But turn up very early 6.30-7.00 am:
That gets you at the beginning of the queue: you'll be given a queue number/ticket by security, then before licensing dept opens a nice lady will walk along the queue to check you've got the relevant paperwork.
If you have, you wait in the queue, if you haven't you go away and come back another day.
Early start = away in an hour or so.
Cusco