change of india's residence address

[cutelinks16]

I am residing in India and our relatives have applied for I-130 form and till now i have not recieved the orignal approval letter from U.S though my file has been approved. I checked from case status online site. As i have changed my residence i , think i have lost that letter, How can i change my address in the U.S immigration so that i can get the other documents from NVC
Please help me...
I want to change my india's address