there will be a way of locking the hinge to take the door off. a lot of them is a flip up piece of metal that jams it so when you lift the door it unhooks
Lift that metal latch (on top of the smaller of the two silver hinges) upwards. Once it’s fully extended (on both hinges) hold the door firmly and close to a point where both latches catch against the stop. Then lift the complete door clear.