How do I change icons in Thunar

[Todd and Margo Chester]

Hi All,

    When I click on an .odt file in Thunar, it starts
Open Office.  This is what it is suppose to do.

    Question:  Thunar's current icon for a .odt file is
IBM's Symphony.  How do I change the icon back to
Open Office's icon?

Many thanks,
-T