Tie Rod Adjustment

[1983/300CD]

I'm trying to adjust the toe, and the outside end of the tie rod won't turn.
I have a style that is clamped on the inside (nearest the engine) and has a nut that tightens the outside end (nearest the tire).
I have loosened the clamp on the inside, and the nut out the outside.
When I turn the tie rod, the inside that was clamped now spins in its threads, but the the outside part does not want to budge. I don't know if I am going to put too much pressure on the ball joint or what kind of damage may come from putting too much torque on it. Is there a technique to doing this? Is there another part on that nut-tightened end that needs to be loosened?