Deleting in word?

I have new toy a Galaxy A6 tablet, on it is Microsoft word, on thatw is a read only document that doesn't allow changes or deletion.
I never put protections on any file I just transfer important ones to external drive via laptop.
Attempts to delete this document is thwarted by " you haven't permission to deleat this file."
How do I over ride /close this permission feature.
In layman's terms please I'm computer technology illiterate
Thank you