How to update your iPhone to latest iOS Apple iPhone 6
Update your old iPhone, anything not iPhone 6 or iPhone 6 Plus is old now, to the latest version of its OS – to iOS 8.
iOS I hear is a huge download. Upgrade needs a lot of space when done OTA, around 6GB. If you’re like me, not a heavy space user and thus being comfortable with even 8GB of memory, you’re going to be in trouble if you plan to update your iOS. Even if you have an iPhone with 16GB memory, it still might not have 6GB free for the update available!How to get around heavy memory requirement of iOS 8?
How to update your iPhone to latest iOS
Don’t do OTA.
Update your phone using iTunes. You know that software you use to sync you iPhone with your computer? Yep, That piece of software!When you next connect iPhone to your Computer it will check for an update to iOS available, and if your iPhone can be upgraded to iOS 8 it will ask you to download the update and thence install it.Source TIME via Apple.