Item and Curricula revisions using FTP

Need to revise an item. I have done a revision before but heard a while back that as an admin, you can ftp into where the area where the content objects are stored and replace the content object with a new folder that has the same files with the same name in the…and it will update the content object in the item without having to revise. Also those who may have taken the course will still have credit without having to do a substitution because there is not one.