Temporarily Removing an iOS Upgrade/Update from an iDevice

Go into the Settings App, General Settings panel.

In the right hand column, tap Storage and iCloud Usage.

At the top in the first block of 3 panels where it is titled at the top of this block Storage, tap the panel that says Manage Storage.

A list of every app will generate itself.

Once this list stops generating, look through this list until you see something like iOS 10.x.x in this list.

Tap on the arrow at the far right on that iOS 10/11.x.x panel.

It will bring you to another screen that will allow you to completely delete/remove the entire iOS upgrade/update.

This removal/deletion of an iOS upgrade/update is not permanent and may return at anytime when the iOS upgrade/update at some point will get re-pushed to your iDevice, where you can simply perform/repeat this procedure, again.