Thanks Jeff F46 for your help. With your tips, I was able to do it. For anybody who is looking back at this post in the future, attached are a couple of photos, and some instructions.
First of all, you have to remove the original BMW wiper blade. If followed Jeff F46's instructions, and used a couple of small flat-bladed screwdriver tips, one above the attachment point and one below. You just have to prise the opening a bit wider, and the wiper blade should then pop out.
Then, you do the same thing to remove the adapter piece from the Bosch A282H wiper blade.
Then, you just push the Bosch A282H wiper blade (without the adapter piece) into the slot in the BMW F46's rear wiper arm. It should snap into place.
I have attached a couple of photos.
The first photo shows the Bosch A282H wiper blade at the top (with the adapter piece removed), and the BMW original one which I removed from my car at the bottom.
The second photo shows the rear wiper arm of the BMW F46 (2-Series Gran Tourer) with the wiper blade removed.
Changing my rear wiper blade to this Bosch A282H resolved my problem with the noisy old one. My car is 5 years old, and I don't think it had ever been changed, so it hasn't done too badly.
The Bosch A282H is very slightly longer than the original BMW one. When it is wiping, it comes extremely close to the underside of the spoiler, when it is in vertical position. But it does not touch the spoiler.