How do I change the settings on the video part.

You might be better converting the video file to MP4, this will compress the video file, but can your Prof. view a MP4 video file.
You can copy the file to a CD or DVD disc (depending upon the size of the video file) and post it.
To create a smaller video file you need to re-create the video at a lower resolution, but this maybe still be too large to send by e-mail.