To change the YouTube video size, you will need to use a Columns widget to help control the size of your YouTube video.
- In your Sitebuilder, go to Widgets.
- Select Popular from the drop-down menu.
- Drag and drop a Columns widget.
- In one of the columns, drag and drop your YouTube video.
- Click on the middle axis bar and drag the bar to the left or right. The video will automatically resize to fit in the space provided.