I did it! Have never done a single car repair in my life, but my husband is in Afghanistan and I'm stuck at home with two little kids and the BMW dealer and repair shop are both 30 minutes away. Followed the instructions and now the AC is blowing cold again. Hallelujah!
One small issue, though...as I was wrestling everything back in place to reassemble it, I managed to pop the metal rod off the control motor. When I finally got the control motor back in place, the rod was back in the top (resting in the round yellow disc) but I don't think it was snapped in or attached. How important is that piece? Any idea what will happen? Hope I haven't made things worse...