Delete Widgets:

You can delete a widget by clicking on the delete button. First, hover over the widget and then, click delete. Any widget you delete will be moved to the recycle bin.

Here is how to delete widgets:

Step 1: Hover over desired widget with your mouse. 
Step 2: Click the delete button (in orange).

See below before and after:
Congratulations you have deleted a widget into the recycle bin! 

Note: The recycle bin contains any widget you have deleted from your website, thus making the delete option reversible.