Installing iOS 17 couldn’t be simpler. Just follow these steps: Open the Settings app Tap General Tap Software Update
On this screen you’ll see the version of iOS you have installed, and if a new version is available it will say so. It may say “Install Now” if the update was already downloaded in the background but not yet applied, or “Download and Install” if you haven’t even downloaded it yet.
Just follow the instructions there to upgrade to iOS 17. You may need to re-agree to terms and conditions, and it will take several minutes to download, verify, and apply.
Then your iPhone will restart, and you’ll be presented with some welcome screens that introduce new features.
We have more information about installing iOS 17 and addressing any issues with it here: How to update to iOS 17 on your iPhone.
If you install an update and want to revert to the previous version there is a very small window in which you can do that, but it can be done.