// edit intro-post-video.php
// replace this line
<iframe width="680" height="383" src="http://www.youtube.com/embed/AFA-rOls8YA?autohide=1&modestbranding=1&showinfo=0" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>
// with 
<iframe width="680" height="383" src="http://www.youtube.com/embed/<?php echo $video->id; ?>?autohide=1&modestbranding=1&showinfo=0" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe>