It is highly suggested that you do this update using iTunes and not OTA. Otherwise you could get your device bricked, which will require factory restore and could lead to data loss https://twitter.com/mvxlr/status/649550081612353537
See this post from Apple developer forums https://web.archive.org/web/20151002074726/https://forums.developer.apple.com/thread/20846 (web archived because apple are shutting that forum down).
See this post from Apple developer forums https://web.archive.org/web/20151002074726/https://forums.developer.apple.com/thread/20846 (web archived because apple are shutting that forum down).
