UPVC lock: WINKHAUS - external door - locking position has moved by 180°?

The locking mechanism has moved round 180° so that when you now unlock the door you can't take the key out. That means that when you leave the house you have to unlock the lock, open the door, lock the door, take the key out, leave the house, put the key back in, unlock the door whilst the door is open, close the door, lock the door take the key out....what a caper!!

How can I turn the lock back inside so that it works properly. Do I have to take the whole door to pieces?

Cheers