Insert key into bottom of lock (at bottom of lock box) turn 90 degrees then lift out silver hasp from top of lock box.
Always open right hand door first, using handles to lever door open (this can sometimes be a little stiff because of the rubber seals).
Key can be left in lock or removed (Key should return to original position)
To relock fully close both doors, insert key and once again turn 90 degrees, drop hasp into lock, make sure key returns to original position and that the hasp is engaged.
If relocking does not happen straight away rattle the lock and hasp around and the hasp should engage.
Remove key once it has returned to original position.