How to change the wipers on your 2012 BMW 320i
1
Remove the old blade
Start on the driver's side. Gently lift the wiper arm on your 320i and release the wiper blade. Blades are typically held in place with a small button to push or tab to pull. Once loosened, most blades will slide right off the wiper arm with some gentle wiggling.
2
Position the new blade
Place the new blade near the connection point on the wiper arm. If the connector on the arm is a hook, put the wiper blade adapter at the open end of the hook. If it's a bayonet, look for a slot on the wiper blade connector about the size of the bayonet and position the blade in front of it. If it's a side pin, make sure the correct adapter is on the wiper blade line up the hole on the side of the wiper with the pin.
3
Attach the blade
Push the blade on to the wiper arm. You'll hear a click when it locks into position.
4
Done!
You're all finished with the driver's side. Repeat the process on the passenger side of your 320i.