Had this same problem when I bought my S80 and i can only imagine its the same problem. I actually had both your problems because one only opened from the inside, one didnt at all. I found out by taking the door panel off the one that did open, that the door opening mechanisim is basically a threaded screw that pushes into a clip of some kind. Not the most well thought out design, but it was easy enough to get in there with a flashlight and see where it needed to go. Its very high up in the door so it can be a bit of a pain to find. But once you get a look at it you can figure it out. As for the door with the broken handle AND child lock, this is where it gets tricky. What I did is got a good look into the door i had the panel off of, remeberd as best i could where the release mechanisem was and well.... Unfolded a coat hanger, rolled down the window and got in there. It took me two tries but only about 10 minutes on the second try. Well, I hope this helps!