As 32Phil said, there is a little S shaped piece that goes on top of the door latch mechanism. Assuming your passenger side latch still works, you can roll down the window all the way and look down from above to see the piece that will be broken or missing from the driver's side.
It is possible to replace it from above. Roll the window all the way down, get an assortment of long nose pliers, a flashlight, and at least two people. And a LOT of patience.
The first few dozen times you try it, the piece will not go in but will drop down to the bottom of the door. You need the bottom door panel off to have access to retrieve it and try again.
It can be done without disassembling the whole door.
Tom