UNPLUG THE MACHINE. Remove the 3 screws on the bottom panel. slide your hand up the right side of the door (below the latch); you will find a small plastic ring. pulling this down will unlatch the door.
the fix the problem you can replace the latch (refer to the manual inside the machine, behind the lower panel, or a number of online resources), BUT first try unplugging and re-seating the connectors (DS3) on the CPU which is under the top cover (remove 3 screws on back and slide cover back then up). i read in the service manual that oxidation is a common problem. that fixed my door latch issue!
mrbellmrbell, October 2008