If you are planning on making changes to an app store widget you should really rename it otherwise if someone updates the widget, they could get a newer version from the app store and not your local changes.
You need to rename the files and contents of the files to match the new name. It’s not enough to just change the .js file. Once all changed, you’ll need to zip it all back up again and rename the .zip extension back to .mpk. Drop this into your application’s widgets directory, then select Project->Synchronise Project Directory in the application, and the widget should appear. If you make changes, make sure you right click over an instance of the widget in the modeller and select “Update all widgets” to ensure your changes are picked up.
Hope this helps!