Which page(s) to search and replace?

Hello,
Which page(s) would I perform a search and replace to change the url of my download links on the products page? I know that I can go in and manually change each one but I’ve got almost 200 products. :O

For instance change http://www.oldurl.com/VideoAudio/Video/CAROL_LESSON.ISO

to

http://www.newurl.com/VideoAudio/Video/CAROL_LESSON.ISO

Please tell me there’s an easier way! 🙂

Thanks, Sam