I'm having the same problem trying to work out how to remove a front door panel from my '95 164 T.Spark.
During a cold spell, I opened the front passenger door from the inside for my wife to get into the car. When she shut the door, it didn't latch. I therefore got out and gave the door a shove to close it. Unfortunately, when I tried to open it later, neither the exterior or interior handles could open the door!! The central locking 'nob' is at a slightly different angle, though (the central locking) still works.
Obviously, removing the door panel of a door which does not open is a problem. Does anyone have any ideas on what to do?
My father and I have taken a look at the driver's door, and it appears the locking mechanism uses cables, rather than metal rods.