To edit an image, audio, or video file you have added to VideoPad in an external editor:
First, right-click the file in the Media List and select "Edit in External Editor..." from the context menu.
If you have specified an external editor in the "Other" tab of the "Options" dialog, then the editor you have chosen will open. Otherwise, the default editor will open (WavePad for audio files, PhotoPad for image files).
Make any changes in the external editor and click save. Close the external editor when the save is complete.
Change back to VideoPad. There should be a message saying "Editing in External Editor... Click Ok when done". Click the Ok button.
VideoPad will reload the file so that your changes are visible.