to remove the dust shield under the engine you'd have to remove 10-12 small screws. easy job.
I changed all water hoses on my X5 and put them back as dry as they were. No grease or anything to lube them. after 3 weeks there are no leaks.
when I changed the water hose from the bottom left radiator I didn't changed the temp sensor. because the washer was old I had a leak once I filled the system with antifreeze. I ran some teflon tape on top of the washer. works like a brand new one.
you're right about filling: key position 2, max temp, low fan and fill until the antifreeze pours back from the bleeder screw.

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2012 X70 XDrive 35i