Turn off the oven, and open its door. Notice the hinges on the corners of the oven door. They are locked to the oven frame with metal latches or a lock.
Flip the latches upward off the hinges, or turn the lock next to each hinge to release the oven door.
Lift the oven door off the oven frame, and place it face down.
Remove the screws from the back frame of the oven door. Remove the back frame, which exposes the metal hinge assemblies on each side of the door.
Remove the screws on the hinge assemblies, and remove the hinges from the door.
Place new hinges in the door, and replace the screws. Replace the back frame and screws.
Fit the door back in the oven frame, and either turn the hinge locks or place the latches over the hinges.