How to Set Background Video With CSS or HTML, YT Background player also not working with my Theme?

I went to the link (http://www.labnol.org/internet/youtube-video-background/27933/) you gave me but i do not understand some of it's instructions such as:

simply paste the code below near the opening <body> tag of your web template.

Where is this found?

this is the file path to a list of what i have editable in my webmatrix : /public_html/irealtygroupcareers/wp-content/themes/vantage

also would clicking on the video lead the visitors to you tube? how to disable this as well if we set this video as our back ground?

http://www.youtube.com/watch?v=TKTVbax3vMI

The YT player doesn't seem to be working? its on our training page ( http://irealtygroupcareers.irghouston.com/?page_id=111 )but its not playing anything..

thank you