HOW TO DO IT...Just had this happen this morning. I put the car in to have central locking fixed and not only is the central locking still stuffed but they didnt put the rod on to unlock the door from outside. I decided to do the rod and deadlocked the door. I had the interior trim off which made this easier. Ok here goes.
You need to get the exterior door handle out. If your interior trim is still on you may need to cut it down towards where the lock is to get to the 2 10mm nuts holding the handle on. Remove the handle and inside you'll see a blue cover over the locking mechanism. It just pulls out. You'll see a bracket in there that has about 4 tabs, this is the lock, get a screw driver and rotate this, it wont need force, you'll see it rotate and the door will open. Once the door is open pull the lock out and play with the same piece you rotated. It'll go into position that it should be. Use the screwdriver to activate the lock the check it unlocks ok. Reassemble.
Hope this helps
Hope this helps.