How to remove a class from the header of a column in a table

My goal was to put a css class on a column of a table so to make a link appear as a button.

First you put a class in the column:

This will it make appear like this:

To remove the button from the header of the column you have to add JavaScript on the page:

TB.render('component_3', function(data) {


and the css-class will be removed from the header (th) of this column:


Thanks @Lee for explaining this. I hope it will help others as well.