It does not matter what div you have the chart in, the video is using a page that has a content are defined by a div so the chart is being inserted in there.
To edit the chart you should go into design view and select the chart on the page, when you do this you should get the options to edit the chart in the properly inspector. If this does not work for you try going into split view and select the code on the page for the chart. Let us know if you have any further problem with this.