I had some in my E body one time that I could'nt get out. I used a pipe wrench w/ a rag around it. Had to knock the hell out of the pipe wrench but got them out with 0 damage.
...is a big-*** cable clamp. I found one for 7/8 inch cable and round-filed the inside until it was perfectly smooth and a tight fit to the t-bar. Then pounded on that with a hammer. This was many years ago...
Last time I pulled them with my bare hands. The key is to get every last bit of tension off them. Tom Condran's book describes it very well.