Few days back, I have tackled the same problem. I started with the front passenger door. Took me the best part of an hour and a half to dismantle it. You first have to take the door panel off. In my case, I didn't use a door panel tool and had no problems. I just used a flat screwdriver and the panel's clips popped off easily without breaking. You need to disconnect and take out the speaker, window switch and power lock switch. You then have to take 1/2 the plastic shield off. Then you'll see your lock actuator right against the door underneath the door lock mechanism and behind the window railing. Rather hard to get to it. You need to remove the window railing and dismantle the lock mechanism from the door itself. You can't just remove the actuator as it is screwed to the lock mechanism and of course the screws are facing the wrong way. Reinstalling everything went quicker (about an hour). Have to be careful when reinstalling that you pay attention to how you reconnect the cables. Make sure you don't leave them in path of the window railing.