update iphone 4s to ios 8.1 without itunes
Notes:
from here
Before you get started
iOS software updates introduce new features that let you do even more with your iPhone, iPad, or iPod touch. Be sure to keep your devices up to date so that you don't miss out on the latest features.Notes:
- Before you make any updates, back up your device to iCloud or iTunes.
- Make sure your device has enough available space to install the update. Tap Settings > General > Usage to see how much space your content uses. Use iTunes to create space if you don't have enough, or remove content from your device.
- If you use your device's Personal Hotspot for your computer's Internet connection, update your device wirelessly or connect your computer to another network.
- If you’re updating from iOS 4.3.x or earlier, you need to update using iTunes.
from here
