if you are feeling up to it you can do it yourself but it takes time.
what hapens is the mechanism inside the latch breaks and the only way to get it open is to cut open the latch here's how.
1) remove the drivers seat from the car.
2) carefully remove the door panel .
3) take out the lower runchannel towards the rear of the door.
4) remove whatever else you can you can gain access to the back of the latch.
5)get out a drill and drill a series of holes through the first plate of the latch if you go to far you will go through the other side of the latch, through the doo, through the jam and so on.
a die grinder helps here also but basically you have to remove the hole mettal plate so you can gain access to the inner mechanisms untill you can get them out and the door will just release.

Make no mistake about this its time consuming and a bitch but if you take it to the dealer thats basically what we have to do so if you can do it yourself you will save a lot on labor.