
The easiest way to do this is to use iCloud, provided you have an account and a plan with enough room to store all your files. If you don’t have an account, simply connect your iPhone with a USB cable to your Mac, or use iTunes on your PC, to copy the content.
If your iPhone is compatible with the latest iOS update, simply go to your phone’s Settings to start the process. Then click on General and then Software Update. You will then be prompted to download and install the latest version of iOS.
Finally, given the size of each major iOS update, it’s better to use a home Wi-Fi network than to rely on a mobile network, especially if you have a limited data plan.
Since the process is quite long, it’s also better to have your iPhone plugged in and charging when you update it. Once the update is downloaded, the device will restart to complete the installation.