Go to Firefox
Launch it
Add on for Video Download Helper can be found here and it needs to be installed
http://www.downloadhelper.net/install.php 
Click on Install on Firefox
Click Add to Firefox
Click Install
Then locate the Video Download Helper multi color icon in the upper right corner of the window> Click on it
Choose what size file to download >
Try to find the biggest choice so your quality is best
The next window will ask where you want to save the downloaded file.
Done you have a file to use in AVID or any other Editing application.