I changed the name of my workbook file a while ago and my process is to make a copy and then publish the copy. The default published workbook name is always wrong and I have to remember to change it which I often don't remember to do. It seems that the default name comes from the ID field in the repository-location field of the xml. Can I just go in with a text editor and change that? There doesn't seem to be a way to change it within Tableau Desktop.
I have not tested this but you can test as I believe this will work fine. Just save a copy first and test. Note that you can also run a test server locally on your license for these sorts of tests if you like.