If you’re like most people with a 16 GB iPhone or iPad, you probably don’t have enough free space on your device to download and install the iOS 8 update using the built-in wireless update method. While the download is only about 1 GB big, in order to download, prepare, and complete the upgrade, your device needs nearly 6 GB of free space. Even I had to free up a little space on my 32 GB iPhone to meet this requirement. If you have a 16 GB iOS device and you don’t want to delete almost everything from your device, there is a way to download and install iOS 8 without requiring so much free space.
Prior to iOS 5, iTunes on a Mac or PC was required to update our iPhones, iPads and iPod Touch devices. Now it is the nearly-forgotten optional method. However, by using iTunes to download and install iOS 8, it is not necessary to clear out so much space from your iOS device. For more information, here is Apple’s support article describing how to use iTunes to update your iOS device. Mashable also has an article discussing using iTunes to update your iOS device.
One tip: if you start the update and iTunes says it will take many hours to download, quit iTunes (confirm that you want to quit since a download is in progress) and then re-launch iTunes. Start the update again and you just might get the download to only take minutes instead of hours. I used this trick twice on an iPhone and iPad to save myself a lot of time waiting!