How to change the wipers on your 2009 BMW 328i
Disconnect the blade
Begin on the driver's side of your 328i. The blade is attached with a pin and held in place with a hook. If you rotate the blade on the pin, the hook will release.
Remove the blade
The blade should freely slide off the pin by pulling it away from the windshield. Set the blade aside.
Attach the adapter
Place the adapter on top of the blade. Line up the 'v' on the adapter with the 'v' on the blade and snap it in to place.
Install the new blade
Place the blade back on the pin. Rotate it back and it will snap into place against the hook.
You're all finished with the driver's side. Repeat the process on the passenger side of your 328i.