thank you very much!
Hello! As far as I know, every time you update your item, you upload a zip archive. In any case, you need to edit the preview file (no one can do it for you).
I think that you should come home and calmly update your item.
I’m afraid to make a mistake, but in my opinion they are only available when online (download a zip archive), but you can ask for support Envato.
Good luck!