if you want the option to restore default settings, I use this code (a function that returns the default column model so we aren't passing in a reference that would be changed by the grid):

function defaultColumnModel(){
return [
{
id: 'request_row',
header: 'Request ID',
dataIndex: 'request_id',
renderer: renderRequest,
align: 'right',
width: 90,
sortable: true,
columnIndex: 0,
hidden: false
},...
];
}

Then I add the button to the bottom toolbar to reload the old configuration:

grid.getBottomToolbar().add([
'->'
, {
text: 'Reset Column Configuration',
handler: function () {
grid.filters.clearFilters();
grid.getColumnModel().setConfig(defaultColumnModel(), false);
}
}
, {
text: 'Clear Filter Data',
handler: function () {
grid.filters.clearFilters();
}
}
]);