PREMISE: This question has been asked previously, but I could not find useful answer on other threads, and, for the reasons I'll now explain, I cannot be satisfied by superficial considerations nor invitations to desist because "is so/too difficult, impossible, etc...".
QUESTION: My mother has a LUMIA 630 with windows phone 8.1; while using it, she had the brilliant idea to download a (wetransfer) .zip file (using internet explorer) of 1.37 GB. Space on phone memory is an issue, now.
So, I'd like to free that space, which means, delete that 1.37GB file, which, many of you will know, is nothing made simple by Microsoft. Needless to say that "files" file manager and other similar apps won't find that file. This question in facts resembles questions on how to get to explore filesystem, gain root access, etc.
Please, help me, and if you're not that experienced, don't answer me "is impossible". Thank you