1) Upload your video to YouTube.
2) Copy the web address of the video.
3) Go to the page in the admin, click on the video icon the the left sidebar, and drag it into your layout.
4) In the box that pops up, paste in the YouTube address.
Tip: If you DO NOT want to show related videos once your video stops playing, add this text to the end of the web address:
That’s a zero, not the letter O.
If you don’t want anything to show other than the play button (see videos below), past in this after the web address: