iOS 10 GM
How to install iOS 10 GM via iTunes with direct IPSW files

Apple recently rolled out the Gold Master (GM) build of iOS 10 to certified Apple developers as well as public beta testers, ahead of the new firmware's final public release on 13 September. Members of Apple's public beta program can now download the final beta version of iOS 10 aka iOS 10 GM by navigating to Settings > General > Software Update.

However, avid iOS fans who want to skip the process of signing up for the beta program can download the iOS 10 GM directly via restorable IPSW files using iTunes.

Prerequisites

  • Back up important data and settings on your iPhone, iPad or iPod Touch via iTunes or iCloud so that you can restore the original firmware if something goes wrong during the upgrade.
  • Verify if your device appears in the hardware compatibility list for iOS 10 (below):

 iPhone

  • iPhone 6s
  • iPhone 6s Plus
  • iPhone 6
  • iPhone 6 Plus
  • iPhone SE
  • iPhone 5s
  • iPhone 5
  • iPhone 5c

 iPad

  • 12.9-inch iPad Pro
  • 9.7-inch iPad Pro
  • iPad Air 2
  • iPad Air
  • iPad 4
  • iPad 3
  • iPad mini 4
  • iPad mini 3

 iPod Touch

iPod Touch 6G (sixth generation)

  • Updating to iOS 10 requires a Mac desktop computer

How to install iOS 10 Gold Master manually without Apple developer account

Step 1: Navigate to the Apple Xcode page and hit the Download button.

Step 2: Sign in with your Apple ID and password. Then you can create a free developer membership, if you don't have one.

Step 3: Click on the 'Download Xcode 8' link to begin the download process.

Step 4: Wait until the download completes and then double click on the file to install it on your Mac. Xcode must be installed on your Mac so that you can upgrade to iOS 10 via iTunes. Otherwise, you get an error message and your device will be erased.

Step 5: Finally, download the iOS 10 GM IPSW file using the links provided below for your specific device:

iPhone

iPhone SE

iPhone 6s, iPhone 6

iPhone 6s Plus, iPhone 6 Plus

iPhone 5s

iPhone 5c, iPhone 5

iPad

9.7 inch iPad Pro

12.9 inch iPad Pro

iPad Mini 4, iPad Mini 3, iPad Air 2

iPad Air, iPad Mini 2

iPad 4th generation

iPod Touch

iPod touch 6th generation

Step 6: You are now all set to install iOS 10 on your device using iTunes.

  • Connect your iDevice to your Mac.
  • Launch iTunes and go to the Summary tab.
  • Press and hold the Option/Alt key and hit the "Update" button. If you want to erase everything on your iPhone and start afresh, then hit the Option/Alt key and click the "Restore" button.
  • Browse and select the iOS 10 IPSW file you downloaded earlier.

Your device will now get updated to iOS 10 via iTunes. Wait until the update is installed and then you can enjoy the latest iOS firmware on your device, ahead of its public release for 13 September.

[Source: iPhone Hacks]