unplugged and with the lid removed look down the inside of the front panel where you will see the tongue of the door latch assy. where it goes through the interlock, with a screwdriver push it to the left and towards you and it should open, if there is a lot of resistance i would suspect a dodgy interlock otherwise check the latch assembly for cracks (if you like try giving the front panel a thump with the heel of your fist first it might release)
keymatic
January 2012