Complicated iOS upgrade - no wifi, no computer So, my niece has an iPhone 4s that I want to help her upgrade from iOS 6.  Easy right? Lets throw in some complications.


Her Wifi is broken. From what I've seen online, this is generally about a bad previous upgrade that didn't get wifi set right. So, this means no OTA updates. A lot of cloud services seem to want Wifi only,  and makes it hard for iCloud backup.
She has no associated computer. From what I've seen before, this may or may not make it possible to do an upgrade at all.  I took those links from an old answer, and I'm wondering if things have changed since then - new iTunes and iOS and all.
She has so much stuff on the device, that she can't do an OTA update - not enough space to download the firmware. She seems to need a computer to download for her phone.
Compounding #3, she is a new mom, and has a lot of pics that can not be lost. Oh, and again, it's hard to offload these with cloud services because of broken wifi.


So, how can I help her upgrade her phone? Is it possible to temporarily use iTunes, say as on a Mac OS X Guest login, have her upgrade, and not worry about iTunes again? It's fine if she blesses that one for downloads and loses it.

The biggest threat is lost media, but without Wifi its hard to use cloud services to get these off.
You can use any computer that has iTunes installed on it. All you need to do is back it up to that computer first. You don't have to sync it with the computer.

Once the iPhone is backed up, you can download and install the update knowing you have a backup of it on the computer.

Once the iOS update is complete, you can go into Preferences -> Devices and then select the backup and delete it from your computer if you don't want it on your computer.