If you can get up there with a little WD-40 and spray a little on the thread, it'll not only make the nut come off easier, but it will also minimize the excess torque put on the stem of the thread and will help prevent them breaking off. Use the little tube that comes on the can and give the nut a little jet. The nut is 7/16" and a nut driver will fit on two of the nuts without problem, but is hard to get on the other two. I sometimes use a pair of long handled needle nose to loosen up the hard to reach ones...Opps, thats ALL of them!!! Good luck, Geof