Please watch this awesome video with Jay Leno and Bruce Porter regarding proper helmet fit. Bruce Porter has worked with Arai for many years and has extensive knowledge on helmets and is one of the nicest people you'll ever meet!
I was lucky enough to meet with him at the Chicago Motorcycle Show last weekend. He spent 5 minutes with me showing me the easiest way to remove the face shield. I know Arai is notorious for having this system, but when it comes down to purchasing your helmet, Fit has to be the 1st priority. If it doesn't fit you, how's that going to protect you?
The 1st video is Bruce and Jay. The 2nd is an Arai video on youtube demonstrating removal. I also found it much easier to have the helmet in front of you facing Away from you as well, if you're not wearing it when swapping out the visor.