Follow the instructions on video.js’s getting started page. In order to integrate with the *Plugin SDK, you must contain the video embed code within the p3sdk-container div. The player_id variable must also be set equal to the video_id variable (highlighted in pink).
<div class="p3sdk-container p3sdk-debug" player_id="video-js" player_type="videojs">
<video id="video-js" class="video-js" controls preload="auto" width="640" height="264" poster="MY_VIDEO_POSTER.jpg" data-setup="{}">
<source src="VIDEO_LINK_HERE" type='video/mp4'>
<source src="MY_VIDEO.webm" type='video/webm'>
<p class="vjs-no-js">
To view this video please enable JavaScript, and consider upgrading to a web browser that
<a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
</p>
</video>
<script src="http://vjs.zencdn.net/5.0.0/video.js"></script>
</div>*The Plugin SDK is sometimes referred to as "P3SDK"