There is a very small pin near the top of the body on one side that needs to be removed. It is callled dowel pin in the pic supplied by 65val, commonly overlooked during disassembly and assembly
I had the same issue in removing mine. Since I had the steering column out of the car I was able to get creative. I don't remember how I did it exactly, but I was able to put something beneath the shaft of the column just above the coupler. Then I drove the dowel pin from the inside out by banging the side of the coupler forcing the dowel pin to hit the shaft work it's way out. You only have to give it light taps. I think that's how I did it.