Josh,
Here is the address where you will need to send the package:
FedEx Express Packaging Lab
2828 Business Park Drive
Bldg H Suite 500
Memphis, TN 38118
800-633-7019
However, you will need to get the paperwork from them first.
This includes the direstions for package submittal and the contract.
Here is the contact info for my rep:
Margaret Biscan
maggie.biscan@fedex.com
If she can't take care of your herself (you may have another rep already assigned to your account) I'm sure that she can point you in the right direction. She has proven herself to be very helpful.
Good luck