Hi all I had the same issue. Rear driver side door stuck. Has been for over a year but just learned to live with it through laziness. Just had a good look at it from the inside as none of the above would open the door. Here's what worked for me:
Took off the door card by undoing the screws behind both handles.
Removed the clip from behind the window winder and took off handle.
Took the door card off.
Removed the speaker via three screws.
Then the tricky bit. Disconnected the wiring loom on the corner behind the speaker by pressing in the blue ring which just popped open the loom connection.
Then with the front door open pulled the rubber elbow containing the wiring from the rear door.
I removed the plastic cover from inside the drivers door sill and undid some of the plastic cable clips to free up some cable.
I then cut the rubber elbow down the centre about a 3cm cut being car full not to catch the cables with a Stanley knife exposing the cables.
Here I found one cable had split completely and two starting to strip.
Bear in mind I am no car expert or electrical expert, all I had to hand was a plastic connector block, I used this to connect the split cable and taped up the exposed cables with some electrical tape.
Taped up the split rubber elbow and put everything back together.
Triad the door from the inside with the door card back on with no joy so tried from the outside and no movement.
Tried unlocking and locking the car from the fob a few times and pulling on the handle at different times with a bit of force.
After about 10 tries the door finally opened.
Now its working and I can open the door to get better access to everything I will do the job properly by using some cable crimps and maybe extending the cables a little as there wasn't much to play around with.
Might work right away for anyone who hasn't left the door for a year unable to open it.
Hope this helps anyone with the same issue.