The easiest way would be to play the DVD on the computer and record what you are hearing. Your computer/sound card may or may not have that capability. I had to download a different version of my driver in order to do it.
This may be different on yours, but choose Control Panel, Sounds and Audio Devices, Sound Recording, Sound Recording Volume. If there is a control for Stereo Mix, select it. Then you can record with sndrec32, or audacity, or other app while the dvd is playing.
Or, you could do this