Hi if i get a Lumia 930/Icon and it has windows 10 mobile and i wanna downgrade to 8.1 Denim , can i do it??? also i read somewhere that you can upgrade from 8.1 to 10 unofficially by changing what your phone is detected as , where can i see if that was changed and how can i get it back to the original?? does the lumia Icon have official upgradeability to W10M ??? is there a way to check with software exactly if every mic works?? thanks