Its me again
On Youtube you just need to click the "share" button and then "embed" and you can get the HTML code for a Youtube video and you can replace the vimeo code then.
jonahh, i already test embed, but it seems the code when i save is gone.
using custom html then add <iframe width="560" height="315" src="https://www.youtube.com/embed/ka-W1FxZuN0?rel=0&showinfo=0
" frameborder="0" allowfullscreen></iframe> with toggle editor. And save it. But dissapeared.