I seem to remember if you can manage to pull the door seal off on the inside with the door closed, then you can manage to get in to de activate the child lock
. (cannot remember if I had to do this on the 75 or the 600)
If this not possible then its a real issue.
You will need to remove the door card with the door closed and then you will see the white clip that is wrapped around the threaded bar in the post on my other thread. you will need to unclip the white clip and refit it so there are less threads showing out of the bottom of the clip. hopefully this will allow you to open the door from the outside.