How to delete downloaded iOS 26.1 update from iPhone?
Removing downloaded IOS software 26.1 from iPhone SE
[Re-Titled by Moderator]
Original Title: Deleting download updates 26.1
iPhone SE (3rd generation)
You don't. There has never been any supported method of downgrading iOS. In fact the same is true for Android devices where many who have tried ending up with a bricked phone. For that reason, Google does not support it either.