After several months of intensive beta testing by developers and public testers, iOS 10 has shipped. It's simple to update your iPhone, iPad or iPod touch to the newest Apple mobile operating system, but if you need a refresher...here it is!
1) Back up your iOS device
Hopefully you've been backing up your iOS device every night by checking Settings > iCloud > Backup to "on". You can also manually run a backup through the same mechanism. If you think that you might want to revert to iOS 9.3.5 (the latest current version) after moving to iOS 10, it's a very good idea to back up to iTunes. This Apple World Today article from yesterday shows you how!
2) Plug your device into power
It can take a while for the update to download and install, so it's always good practice to plug your device in so that it's receiving a good constant flow of power during the installation.
3) Begin the update
In the iOS Settings app, tap General > Software Update. If it is still showing "iOS 9.3.5 Your software is up to date" then the update hasn't made it to your local Content Delivery Network node. Don't worry, it'll be there soon so just keep checking back.
If it shows that the update is available, a description of iOS 10 appears:
That pretty much sums up iOS 10 in one big list. Scroll down and tap the "Download and Install" button. You're asked to enter your passcode, then agree to terms and conditions. Once that's done, the installer pauses temporarily while it gets into a queue for downloading the software, then begins downloading.
4) Patiently wait for the installation to complete
With millions of people waiting to download and install iOS 10, it will definitely take a bit of time today. Be patient. Go read a book, take a walk, or do something else for a while.
5) Follow the instructions to finish the installation
Once iOS 10 is installed, you'll need to log into iCloud once again with your Apple ID and may have other actions to take. Simply follow the instructions provided by Apple and you'll be back up and running in no time. Enjoy iOS 10!