Me and Nirvit da are trying to follow the following process whic was successfully executed by ShamimBD
The process I followed is as bellow:
1) I created an account online with FedEx USA
2) Then, I created a shipment online to send my passport to SGVO address. I selected the document type: Passports. I also selected the service type: international priority and package type: FedEx envelope. I paid the charge online using my credit card. When the shipment was created, I printed the label for sending my passport to SGVO. I took my passport and other documents to a FedEx office. They provided the envelope, took my printed label and attached with the envelope. They will not charge anything again.
3) When I created the shipment there was also an option to create return shipment but I did not find any option to choose from Singapore to USA. Then, I contacted with FedEx office and they informed me that to make a return shipment, you have to login to Singapore FedEx site with the same username & password I used to create my account with FedEx USA.
4) I followed the same process to create the return shipment from SGVO to my address after login to Singapore FedEx website. In this case, I used the document type: Immigration documents. Here, the problem is that you don't know when SGVO is going to return your passport. Also, the FedEx website will give you to make any shipment for next 10 days only (I forgot exact days). So you will not be able to choose a date of shipping one month later from today. I used the maximum late date that the website allowed me to create for return shipment. Here, I talked with FedEx office, they informed me that if the return date is within 2-3 weeks of the date specified in the shipment, it is OK and there is no problem. But if it is too late like 4-5 weeks, Singapore FedEx may charge some additional money from your credit card. For my case, they did not charge any. I also printed this shipment label and took to the FedEx office. They attached the label with an envelope and put inside the envelope that I was sending to SGVO.
5) I also requested in the cover letter to SGVO to inform FedEx office when my passport is ready to send so that they can pick up the envelope from SGVO. I provided the FedEx office number of Singapore found in the web and told to follow if they have any other better way to inform FedEx Singapore that a package is ready to pick up. I think FedEx regularly visits to SGVO for pick up and drop off letters, so that is not a problem.
6) When I was creating the return shipment I selected the Pickup/Drop-off: Drop off package at FedEx location.
7) There is also an option when you create the shipment that you will be notified through email about your shipment's processing. So, FedEx will send you an email notification, when they get the envelope to process from SGVO and you know that your passport is coming back to you.
It took 5 business days to reach my package to SGVO but the return service was pretty fast. I received it with 2 days after shipping from SGVO.
I hope the above information will help.
