To edit a File Name directly from the file list, so that you don't have to open the file first:
Hover over the file.
Click the Edit icon just to the right of the filename.
Change the name.
Hit Enter on your keyboard to save.
To edit a File Name while previewing that file:
Click on the name of the file you'd like to edit.
Click the Edit icon in the upper-right corner.
3. Click the File Name box and type a new file name.
4. Click Save Changes.