How to partially change the default stylesheet for the current Notebook

Is there a way to make a minor modification of the default appearance of cells in the current Notebook without specifying the a开发者_JAVA技巧ll set of options? For example, I wish to have all Cells with style "Text" in the current Notebook by default having

 CellMargins -> {{Inherited, Inherited}, {0, Inherited}}

All the other options should be inherited from the default stylesheet. How can I achieve this?

Open up Edit stylesheet from Format menu.

Then paste there the following:

Cell[StyleData["Text"], 
 CellMargins -> {{Inherited, Inherited}, {0, Inherited}}]

EDIT: Adding a screen-shot: