many thanks Andrew just repaired it. I will add also ->
After you unlock the door (see Andrews post) undo 5 screws that are on the top of the door on the inside. Mentioned screws hold control panel on the outside. Than unscrew whole locking mechanism (4 screws) inside the panel and pull out smallest plastic pin.
If we don't count plastic pieces that are broken, you should have 5 parts in your hand: plastic pin, a spring, the handle and plastic part of the mechanism.
The problem is that 2 small pieces on the handle are broken and can no longer pull the mechanism in order to unlock the door. I used hot glue in order to attach the handle back on the mechanism. Works for now.
Assemble in opposite order.
Ariston model: Ariella
Karletto
March 2010