Unfortunately, you can’t do that yourself—most likely the English audio track does not reside on the video you have. It’s just a copy. You have to find whomever originally recorded the video and then dubbed over the new language (or a company that sells it) and ask for a copy of the original version in English. What is the video of? If it’s a movie, the English audio track may be hidden on your copy and can be retrieved through a menu. But I’m suspecting it’s some other kind of video. Can you give any additional information?

Thank you for your response.

It’s a clip from an American tv show. I really enjoyed this particular part of the episode and was able to find it on youtube but to my dismay, it had been dubbed over. I was curious if it could be put back to English. I think the language is in Spanish.

Do a Goggle search. You may get lucky and find it for rental or sale, or at least find a contact number.

You might be able to find the original, un-dubbed broadcast by searching the torrents.