Well, i seem to lock myself out a lot(seems like i don't learn my lesson). the first time i had to call a locksmith and i watched how he opened it. i've been doing it every time now.
First find a piece of rock or any other thin piece of metal or something. It has to be about half an inch or so. then try to pull the door open from the top, and slowly insert the rock into the open gap so that it holds the door open for you. the wider you can pull the door open, the easier. From then on just insert the hanger in the gap, and try to get the hanger to open the latch.
It takes a lot of patience though. it also depends on what type of lock ( my car doesn't have the one that you push down to lock.
And finally, please don't do this for illegal purpose. thank you