As we all know, this is a forum for Kingdom Hearts. Even so, if anybody posts spoilers for Endgame anywhere on this site without spoiler tags, you will be banned.
If you change your avatar to something related to Endgame, you will be banned.
If you put something in your signature, send a message to somebody that is visibly seen, or share spoilers with somebody who does not wish to see them, you will be banned.
This isn't possible, unless you own the best audio engineering equipment and even then that won't be able to help you EQ the frequencies out totally. You absolutely need the original file, like others have said.
I know I cannot remove the vocals entirely but I cannot find an instrumental version of this song. It appears to be from a private company so there isn't any instrumental songs and I cannot entirely remove the voices at all.