It can take anywhere from 15 mins to an hour for the update to download and install, depending on how Apple’s servers are handling the load and your internet connection.You may also want to connect your i Phone to your local Wi Fi network, so you don’t get charged for downloading the update over your cellular connection. i OS will automatically check for available updates and will prompt you if one is available.Make a wise decision now Before upgrading to i OS 10, the first thing you need to do is checking the full list of i OS 10 compatible devices and see if your i Phone, i Pad or i Pod touch can run i OS 10.Read this post to learn complete i OS 10 compatible device list.Before you start the download, plug in your device so the battery doesn’t drain during the update process.It can take anywhere from a few mins to an hour for the update to download and install, depending on how Apple’s servers are handling the load and your internet connection.
If you have jailbroken your i OS device and cannot live without your favorite jailbreak apps and tweaks then it is recommended that you avoid updating to i OS 9, until Pangu or the Tai G team release a tool to jailbreak i OS 9.
If your i Phone or i Pod touch is already in recovery mode, you can go ahead and restore it using i Tunes.
If i Tunes displayed an alert with an error code, go to THIS Apple Support article before going through the procedure presented here.
There are two ways to upgrade your i OS device — over-the-air via your device’s wireless connection or by connecting your i OS device to your computer and letting i Tunes do most of the work.
Updating your device wirelessly Before you start the download, plug in your device so the battery doesn’t drain during the update process.