One would think that renaming a file on Mac must be easy given the user-friendliness of Mac OS. Turns out, it is not so obvious.
To rename a file in Finder, you click on the icon preceding the file name once and then click on the file name again. This will highlight the file minus the extension. Now you can type the new name to rename.
Having said that, I was able to create a Automator script that will pop-up a dialog to rename either part of the file (base or extension) by right-clicking and selecting the Services option.
Following is the snapshot of the Automator script.