1. Edit the WordPress Page or Post in question
  2. Click the text tab
  3. Locate your embed code
  4. Locate the src="youtubeurlhere"
  5. At the end of the youtubeurlhere add the following: ?autoplay=0&rel=0
  6. The URL should then look like srce="youtubeurlhere?autoplay=0&rel=0"
  7. Click Update