What I did to get the nut under the master cylinder was put a 6 point socket on a long breaker bar, pull that big connector off it's mount and move it out of the way. Then stick the breaker bar down through there and get the socket on the nut. I may have used a prybar, or a piece of wood strapping to keep the socket from falling off, I can't remember. Then I went under in the wheel well, broke off the "flag", and loosened it with a ratchet. I had the strut removed to gain access to the bolt, I was either changing the strut on the same day, or the strut rod bushings, I can't remember. I should have taken pictures.
Rich, you were able to get at the bolt by letting the air out of the strut? I didn't even think of that....maybe next time, I'll try it.