just had this same problem with my third. the bottom 3 studs were pushed up from hitting rocks and thus i couldnt get the third off. a little tapping with a hammer and prying with a long screw driver got them straight enough to get it off. now ive just got to replace those three studs.
Mine was the same way. Had a real wrestling match with it & it still would not come out until we tapped the studs square.
