Week 1 The notebook you provided has a syntax error that prevents it from compiling

You can do “File → Rename” to rename your notebook out of the way. As pointed out in the instructions here, the “Get Latest Version” won’t over-write an existing file, so you need to move or delete the original file first.

Just for informational purposes, the way to delete a file is to click “File → Open” from the notebook and that gives you a “File Navigation” view of the assignment. From there, you can find several ways to delete a file.