Good question. Most just upload the new file and delete older files eventually, I guess. If you use the butler app, there should be explanations on how to push updates.
They have that butler app that is supposed to handle this.
There is no replace file with file button on webpage that I know of. But you can have different versions on the same page and since they do have that butler, I guess, they see no need for any such button. Uploading new stuff and deleting old will do the same.