How do i make a Video Embedded at Grabcad?

you need to upload it on for example youtube, and then copy link below video and paste it in Link to video field in upload cad model form

You've put the shortened link, open the video in YouTube, delete '&feature=youtu.be' from the link and copy the rest then put it here on GC.
Your ring video link should look like this: http://www.youtube.com/watch?v=z6qRtRlbZ-M.

Is it possible to have multiple videos for one file?