ZJ tie rod question

Ok. I'm a newbie.
Now that thats out of the way... There are two tie rod ends. One is threaded into the adjustment collar.
The other has no threads or way to remove it that I can see.
How do I replace the one NOT in the adjustment collar? It spins when I try to get the castle nut on it. I'm pretty sure it shouldn't do that...

That would be the "draglink"(not tie-rod) and must be replaced as a complete unit.

no, the v8 zj tie rod has one adjustable end and one fixed end. I just put one on mine.

Regardless, you'll have to replace the entire shaft. Go to the junkyard! I got the whole tie rod, end to end, for $8.