Anyone here change them? I mean, wow, what is up with that design? Anyone have any tricks? I am trying to not round the nut on the fitting that attaches to the brake line. Also, for some reason, 17MM seems to big, but a 16MM does not fit.

 

I haven't changed them on my 3, but they appear the same as other vehicles i've had. The fitment problem can easily be corrosion - dunno the age of your car. You may need or want to try vicegrips. They are tight in general, use some penetrating lube on it and hope for the best.