by David Kanter
July 2, 2011
This article will cover how to upgrade from iOS 4 to iOS 5 using an iPhone or an iPod touch on your Mac. At the time of this publication the latest version of iOS is 5 beta 2. It is recommend that you do not use your primary iPhone for this procedure, as it is a beta and meant for developers to test. That being said, I did this on my primary phone, and played with the beta for a few weeks, but there were too many critical apps for my workflow such as Evernote, Dropbox, and, well, the Phone app that didn't work for me. I went back to iOS 4 after two weeks. I will outline the steps needed to upgrade to iOS 5 as a registered Apple developer, although Bryan M. Wolfe covered a voiceover activation hack from Gizmodo that apparently lets you get past the activation screen without registering as a developer on the first iOS 5 beta (I haven't tried this). My follow up article will cover how to downgrade from iOS 5 to iOS 4 despite warnings from Apple that it isn't possible. Bryan also covers an interesting story on that topic in Apple To Take New Measures Against Firmware Downgraders. Okay, enough of the warnings, if you want to live on the wild side, here are the steps for upgrading from iOS 4 to iOS 5:
1. Backup your existing iPhone by plugging it into iTunes via the USB cable and control-click your iDevice, then choose "Back Up" from the menu that pops out.Apple Developer Portal, go to the iOS Dev Center and click the iOS SDK beta filter. Go to Downloads, download iTunes 10.5 beta 2 as well as the correct iOS 5 beta for your iPhone. There are several depending on your model iPhone/iPod touch, see screenshot below for the right one.
Provisioning Portal. 4. Install iTunes 10.5 beta 2 on your Mac. 5. Open the image of the iPhone 5 .ipsw file and drag it to your desktop. With your USB cable plugged in, highlight your iDevice in iTunes, and option-click the Restore button. When the dialog box pops up, choose the .ipsw file you put on your desktop and select it from the File dialog box.