Do you use RealPlayer and the associated line of Real products? If not, Google it and download it, it is free.
Now while the video is playing, hover your mouse over the upper right hand corner, a little blue thing should pop up that says "download this video" - click on it. The download will commence, and be quick.
Now go to wherever downloads go on your computer, or just click on the Start button and search for the name, and find the video. Go to the Real folder and open the program called "RealPlayer Converter"; open it and drag and drop the video into the program. Tell the program to convert to "MP3 only."
There you go! A MP3 copy!