Stopping iOS updates and getting rid of downloaded but not installed updates

The following is a note derived from the following extremely useful post by SergZak at:

https://discussions.apple.com/docs/DOC-9741


I don't want my iOS devices updated to iOS 10 as they work well at the moment and I've previously found Apple allow devices to be updated to a point at which their performance suffers.

To stop updates I've blocked mesu.apple.com using OpenDNS (which I use on my router).

I've also deleted the previously downloaded update by finding the iOS update app at:

Settings

General

Storage & iCloud Usage

Manage Storage. 

There I found the iOS update app. By tapping on the app I could delete the app.

Once again, many thanks SergZak !