May I know the procedure of tax-refund,please? 我想了解一下退税的程序，可以吗？

There is a detailed introduction on that board.Please have a look at it. 在那个公告板上有详细的介绍，请您自己去看看。

Can you tell me how to draw back the duties,please? 请问你能告诉我如何办理退税吗？

Can you tell me how to draw back the duties,please? 请问你能告诉我如何办理退税吗？

Sorry,I don't know. 很抱歉，我不知道。