在使用c#导入到datagridview之前，删除一些基于单元格值的行。

I am trying to import excel file to datagridview from stoarage. With the following code I can successfully uploaded two column from my excel file. But I want to modify my excel file progmamicaly before importing it. In my excel sheet one column contain City name and other column contain population number. I want to delete the row which contain lower that 10,000 people. But I really do not know how to do it. Here is the code by which I imported excel file.I am trying to import excel file to datagridvie