Thanks very much! You're awesome.
It mentions two procedures:
1) Just send a self-addressed return envelope and they will return documents by USPS. It however does not mention if this envelope should have postage stamps affixed or not?
Strangely, they have made it clear in case of addresses inside US (that postage has to be paid by applicant).
2) FedEx courier with an airway bill and returned courier envelope. Both sender and recipient section should show the applicant's name and address (I guess sender's address would be Canada even if the package is originating from US??
) and most importantly, applicant's FedEx account # for billing purpose (no check or credit card accepted). Since I don't have a FedEx account, I guess I should open one with them and then use this option.
Thanks again. Much appreciated!