I know squat about html, but I do understand the windows directory structure. So instead of just unzipping your file, I poked around first, and… I see there is a root.webfolder file. The head scratching begins. Where are all of the other files in your archive. So, I see that the root.webfolder is actually some sort of archive file, that I can unzip, but I cannot just rename your file and replace the current one (did that make sense.)
So I have to wonder, what kind of archive file is it? It would seem to be easier to just replace a single file with another, instead of unzipping into the program directory.
Yeah… a little knowledge is always dangerous.