Thanks to the OP for this DIY. I've got a 2007 328i Wagon (E91) with 151k miles. Original arms and the bushings gave out God knows when. The dealer noted I needed new bushings when I brought the car in to have the Takata airbag replaced as part of the recall. They did a full complimentary inspection as well. (I suppose to see if they could do some repairs and overcharge the living hell out of me)
The dealer wanted $950 to replace the bushings. I got the Meyle HD arms for $150 pair instead and replaced them this weekend. Took about 1.5 hours. Used a cordless impact wrench to loosen the nuts free. Then used a T40 to hold the stud on the control arm in combination with a 21mm open end box wrench to remove the nut completely. Same as Rotorocious described in post #4.
Had the same problem as others when torquing the nuts back down during installation in that the entire steering rack wanted to turn, same as post #52. Had my son come out and hold the steering wheel while I torqued the nuts. That worked like a charm and he's 11.
Car feels much tighter on the front end. Had no idea what I was missing.