When you upload a video to DEVOS and you want to replace it after it is published, follow these steps:
1) Log in to DEVOS and select edit of the target video
2) In the upper corner of the edit page, next to the "Download Video (Right-Click and Save As)", note the alpha-numeric code. For example: 92b902382bd5
This code is used to identify the video you wish to replace.
3) Find the video you wish to upload as a replacement and rename it using the above code plus ".mp4". For example, rename "myvideo.mp4" to "92b902382bd5.mp4"
5) Use a FTP program and log in to you account. Remember, your FTP username is shown on your profile page and your password is your DEVOS password.
6) Select the folder /content and then the folder /replace (e.g. /content/replace) and upload the new file.
Within a few minutes, the file will disappear from the FTP folder (you may have to refresh your FTP client to see it gone), and the new video has replaced the old.
Note that this action overwrites the old video and after update the old video no longer exists.