Turn ON your wipers then turn off your BMW 1600 when the wipers are at their mid-way point on your windshield
With your wipers stopped midway on your windshield it should be easy to lift your wipers up and away from your windshield.
Your old wipers should stick out, away, from your windshield. Now allowing for easy access during the rest of the changing process.
Be sure to take note of which new blade length goes on which side.
Measure or just compare old blade length to the new Trico® wiper blades.
Then place the new blades on the correct side.
Your 1968 BMW 1600 has a small hook attachment for the windshield wipers to connect with.
Different wiper manufacturers use different style attachments for the small hook. Look for a button or a latch to lift and slide off the old wiper blade.
Slide the new blade on to the hook and push the blade in to the armhook until it locks in place.
Double check that wiper blades and adapters are locked on to the wiper arms.
Carefully lower your new wipers down to your windshield. Discard old wipers and packaging material.