The fortwo 451 uses Bosch Aerotwin wiper blades which are very easy to change.

Replacements have the following part numbers: A294S or 3397007294. Please note that only that they must be direct fit Aerotwins.

Squeeze the sides as shown.

Pull the wiper blade as shown. It will come free and pivot around the front of the arm (circled).

Replace with a new blade in reverse order.