It's really quite easy to do - the NN5 user manual explains what you do. It will take you no more than 10-15 mins to set it exactly. The detent rings allow you to set the noumber of click stops for a full 360 degree rotation. the numner of click stops you need dpends on the field of view of your lens as you need a 20-30% overlap between frames for a good stitch.
Ok found out what the problem was with finding the pupil entry point.I was always pretty close but the canon photostich software was not up to the job. i have now trialed PTGui and found the panoramics marry together very well with that software