You need a 22mm (iirc) crows foot and a long extention and breaker bar and it will come right off. Take the small panel out of the inner wheel well, knock off the one time use clamp on the boot and slide it back to access the inner rod.

50% of the time or more, the outer rod will be stuck to the inner and there isn't enough PB blaster in the world to break it free. The bolt is long so it rarely gets in there far enough. It's not worth the hassle and time wasted, with no guarantee you will actually get it off, so changing both is usually my practice also.