Even if you don't use butler, as long as you upload your file with the same filename as before, it should replace the previously updated file. You can see that file updating with a progress bar on the page, or see it uploading as a new file if you accidentally used a new filename, and afterwards you can view your page and see the upload date has been updated. I was doing this for a long time, but I started using butler recently. Similar deal, as long as you use the same channel name when you upload, it'll update the same file, or create a new one if you accidentally type a different channel name.