This wikiHow teaches you how to install an earlier version of iOS on an iPhone using iTunes on a computer.
Step
Step 1. Check the iOS version currently on the device
You can check the iOS version you are currently using via the options General in the Settings (settings) on iPhone, then tap About (about). The current iOS version will be indicated next to the text Version (version).
Step 2. Backup your phone
Step 3. Search for the IPSW file on Google
You need an iPhone Software File (IPSW) to be able to manually install iOS software on iPhone. Make sure you include the device model and iOS version you're looking for in the Google search engine. For example, if you want to install iOS 10.2 on your iPhone 6S, type “IPSW iOS 10.2 iPhone 6S” in the search engine box.
You can also visit IPSW.me to find the file you're looking for. This site has archives of the latest IPSW files for older iOS versions
Step 4. Download the IPSW file on your computer
This file will only be used for iOS installation. You can delete it from your computer once you've finished installing iOS.
IPSW files for older iOS versions usually Unsigned (unsigned). This means that the file is no longer authorized by Apple. If you want to install IPSW Unsigned on iPhone, the device must be jailbroken (hijacked) first. Read this article to learn about the process.
Step 5. Open iTunes on the computer
You can use iTunes to manually install the IPSW file on your iPhone.
Step 6. Connect iPhone with computer
Use a USB cable to connect the two.
Step 7. Click the iPhone icon
It's below the play button in the upper-left corner of iTunes.
Step 8. Click Summary on the left navigation menu
It is located at the very top of the Settings menu.
Step 9. Click specifically on Restore iPhone
- On a Mac, press and hold Option on your keyboard, then click Restore iPhone.
- On a PC, press and hold the alt=""Image" key on your keyboard, then click Restore iPhone.</li" />
Step 10. Select the IPSW file you want to install
Locate the downloaded IPSW file, and click to select it.
Step 11. Click Open
iTunes will open the IPSW file and begin the installation process on your iPhone.
Step 12. Click Restore
iTunes will delete the current iPhone software, and replace it with the downloaded IPSW file. If you installed the IPSW file for iOS 10.2, your iPhone will now be running iOS 10.2.
