Here is a quick tutorial on how to downgrade iOS 12.3 to iOS 12.2 on the iPhone, iPad or iPod touch right now using iTunes on Windows or Mac.
iOS 12.3 is here, finally. But you didn't want that update at all and probably made a mistake downloading it. It's OK. We're here to help and will show you how you can downgrade iOS 12.3 to iOS 12.2 right now using the magic of iTunes. But remember one thing: this is something which you can do for a limited time only. Once the downgrade window closes, you have no option but to stick with iOS 12.3. Are we absolutely clear about that? Good.
Before you go ahead, if you haven't downloaded iOS 12.3 yet and have the desire to install it right away, then be sure to check out the following:
If you have decided that you have to downgrade iOS 12.3 to iOS 12.2, then be vary of the fact that all of your data and files will be deleted from your iPhone and iPad. So in order to avoid this tragedy, please backup your data using iTunes or iCloud and then follow the rest of the guide down to its very core.
1. Turn off Find my iPhone on your iPhone, iPad or iPod touch. You can do so by going to Settings, then tapping on the iCloud section at the very top, then tap on iCloud again, then select Find My iPhone.
2. Download the iOS 12.2 IPSW file from here.
3. Connect your device to your PC or Mac using a Lightning cable and then launch iTunes.
4. Once your device has been detected, it will show up in the top left hand corner of iTunes. Click to open it up.
5. Now click on the Restore iPhone button while holding down the left Shift key (PC) or the left Option key (Mac).
6. Select the iOS 12.2 file you downloaded in step 2.
7. iTunes will now start to extract the content of the firmware and restore it onto your device. This entire process may take up to twenty minutes at best. Take this time to grab yourself a cup of coffee.
Once the installation is complete, you'll boot straight into the Hello screen. You can either setup your device fresh or just restore the backup which you took prior to the installation.