This is a template related statement/question. It would be best to ask the developer of the Skyfall Theme.
You can reach their discord here.
Please edit your original post with exactly what the issue is you are dealing with in detail. Also, please don't repost to bring your thread to the top.
Veuillez modifier votre message d'origine en precisant exactement le proleme que vous traitez. Aussi, veuillez ne pas republier pour amener votre fil au sommet.
^ Like he said you are allowed to remove branding, but it would be nice if you would have a custom page with credit where it's due as Samerton and some other devs do push changes/updates on their free time and work mostly for free.
If you wanna do a true reset, wipe/create a new database, readd all the files and set it up again. Takes a bit but worth it !