jqGrid reloadGrid并刷新新的colModel和colname

I'm trying to reload a jqGrid with new rows, colNames and colModel. The row data seems to load fine but the columns don't seem to be refreshed. I've tried using GridUnload and GridDestroy but I end up losing the jQuery DOM instance entirely and no longer loads any data as well. I'm trying to reload a jqGrid with new rows, co