Either through UPS or FedEX, you must ship the firearms overnight (handguns, not longarms. longarms can be shipped standard).
DHL or whatever their name is will not ship any firearms, for any reason. Period. Asshats.
UPS guys might give you shit for sending the firearm and say it is not legal for you (as a non-licensed person) to ship the handgun, but you will need to correct them. They will have a book with their rules pertaining to shipping firearms behind the counter. Trust me, I know.
Their (UPS) rules is that a non-FFL can legally ship a handgun to a FFL, licensed dealer, licensed gunsmith, manufacturer, or similar. The idiot behind the counter might say that they need a copy of the recipients license before they will ship, just reffer back to their own regulations and show them that you do not need to. If they won't ship it, talk to their manager. I had to teach a woman with "21 years experience" how to read and comprehend english so she could understand UPS regulations.