how to get a boarding pass if i any one residing at china and will have to fly to india

if any one is now in china and booked a ticket from an indian travel agency to fly india from Kunming ,china. he has got the E-Ticket and Airline PNR No., how can one get the Boarding Pass by the E-Ticet Number and Atrline PNR No. at the Kunming Airport.

Tapas Choudhury