How do I change the header on a dynamic widget?

Please follow this screencast:

If you have any further questions, please let us know.

Thank you!

So do I have to type the new name and spacing into the box?  Is there a way to click on the header text and change it directly?  Is there also a more friendly way to adjust the size of the column text and adjust the spacing in a more direct (graphical) way?

There's no other way to change the header text of the Matrix Dynamic widget. To change it, please follow the screencast guide that my colleague provided.

The only way to change the column size is by changing the numbers after the Header Text. 

I hope this helps.