Find the plastic cover where the wiper arm attaches to the car. Loosen the side of the cover closest to you first and then the side furthest away from you. Lift the plastic cover up fully. This will give you access to the hose connector.
Disconnect the hose from the connector. You might need to wiggle it to get it loose.
Grasp the centre of the wiper arm and lift it up and away from the rear windscreen. You may feel some resistance halfway – this is the lock position. You need to pull the wiper arm past the lock position so that it doesn't fall back onto the windscreen.
Pull the blade down until it loosens and comes away from the wiper arm.
Press the new blade into place until you hear a click.
Check that the blade is firmly attached to the wiper arm.
Fold the arm back down against the windscreen.
Connect the wiper blade's hose to the hose connector. Lower the plastic cover back down.
Note
Make sure that the hose is positioned in such a way that it won't become trapped or pinched when the plastic cover is lowered back down.