Door won't open

Im sorry to say, but the housing will have to come off to unlatch the door from the inside.Not difficult ,Unplug the unit and remove all of the screws around the top of the housing cover if any,also
rear and both sides will have to come out.When they have all been removed, lift the rear of the top housing cover and pull back.You will be able to see where the two door latches are locked in place.With a screwdriver,you can push up on the bottom latch and the door will open. All this can be done without spilling the milk inside.Just slide the microwave around slowly to get to the screws.The broken part inside should be able to be replaced.Contact repair parts center.