I believe they put dollies under the wheels to get it up on a trailer or use a tow truck and lift the front wheels and tow on back wheels.I am sorry I don't have a better answer. How do the repossession people do this? They would most likely not have the keys. I don't know how much it would cost but most cars come with key codes. I believe a dealer can cut new keys from the key codes. Not sure how this works if the car has a passive anti theft system. Good luck.
Scott