I'm trying to override editable grid panel css class .

Basically I'm trying to replace some style properties of the panel. For example, if I add the following code in my css file

    background-image: none;
    background-color: #bbaaaa;
    font-size: 25px;
    font-family: Agency FB;
I'm perfectly able to override each style property and make the grid panel header as I need.

Next step is try to do it dinamically by the code, I'd like to remove the default css class and adding them run-time with new style property value.

I saw that there is the following method

but it seems not work, because I still have each default style properties showed by the panel.

Do you know if is it possible to remove a css class and re-add it dinamically?