just did this tonight. one item of feedback, i think step 10 (reattach sensor) should be moved to between 8 and 9. I found it really hard to insert the sensor after the calipers were remounted. After futzing for a while, i gave in and took the calipers back off. After that, I could put the sensor in but it wouldn't stay in firmly.
Finally I compared the new sensor with the old one and discovered that the lip behind the metal clip that holds it in had chipped off, probably during the futzing when the calipers were mounted. It was a third party sensor and the plastic seemed pretty solid, but not as hard as the BMW sensor. I didn't use any tools on it, no banging on it, just finger tip stuff since at the awkward angle it was when mounted, I couldn't get much force on it anyway.
Since I didn't have another sensor handy and stores were closed, I ended up pulling the wheel well shroud *again* and unplugged the new broken sensor and reassembled everything without a sensor and will have to do it all again when I get another sensor.
So that's why I think the DIY should tell users to put the sensor back in before remounting the calipers, so you can more easily see what you are doing and have it at a better angle.
Anyhow, apart from that, the brakes seem to work but I have more travel on the brake pedal now and it seems mushier in the first half of the travel, but then stops hard in the second half. Should I be concerned and what can i do about the mushiness?