On my Campy Bar ends the threading is left hand so maybe somebody didn't know that. There are allen style easy outs that may work. Again ,on my Campy ones , I think the hex is a through hole. I just rewrapped the bars on my Mondia and I had forgotten , when I went to remove the bar ends I realized that I was putting too much pressure on the wrench and then I remembered! Doh!! Lucky for me it was prior to stripping the hex.