Samsung B1445 Door Lock Broken

I would get an engineer to look at it. The laundry is unlikely to suffer any harm if left in although I appreciate certain items may be particularly delicate or even required for urgent use. The trouble is you may damage something further by forcing the door. I've seen it done many times. An engineer may subsequently need to order parts causing a delay, where he may have been able to open it without further damage.

Ignoring all that, if you simply have to get it open then if you can guarantee the machine is disconnected from the electricity supply the top would need to come off and attention paid to the door interlock. If the interlock is jammed, the screws to undo it are at the other side of the door, which you can't get to without opening the door so if it can't be manipulated open it will have to be forced open somehow doing as little damage as possible.