iOS 16 Beta

It took me also a long time to remove iOS 16 from my iPhone Xs. This page helped me a lot.

https://www.maclife.de/ratgeber/ios-121-beta-verlassen-apples-beta-programm-ios-12-100120990.html

This page is in German and you can translate it with a translator by your self if you want to read the whole thing. But what it basically says is:

To reinstall iOS 15 you need an Mac with the latest macOS. Connect your iPhone with a cable to the mac and start the Recovery Mode. Running the Recovery Mode will delete everything on your iPhone. To start the Recovery Mode you have to do following:

• iPhone 7 and iPhone 7 Plus: Press and hold the Side Button and the Volume Down Button at the same time. You keep holding this two buttons even if the iPhone did shutdown and the apple icon appears. You still keep holding, till you see on the screen that the Recovery Mode started.
• iPhone 8 and newer: Press quick Volume Up Button, than Volume Down Button and than press and keep holding the Side Button till the Recovery Mode started. You keep holding the Side button even if the iPhone did shutdown and the apple icon appears. You still keep holding, till you see on the screen that the Recovery Mode started.

Now on you Mac a window appears with the option "Recovery", "Reset", "Restore" or something similar. I don't know how to translate the German option correctly. In German it says "Wiederherstellen".

Now the iPhone should delete everything and reinstall iOS 15. If you made an iOS 15 Backup before you installed iOS 16, now you install it.

I hope this helps you.