What do I do about One Note update on iPhone that is taking over a day to complete?

[iMore Question]

The update of One Note on my iPhone is going on 2 days. I don't know what to do. On the app update page the button is unresponsive. The app icon is grey and beneath it the message reads 'waiting...'

 

[Smply_Rckless]

Try canceling the update, uninstall the app, then re download it