Help with lower ball joint & Tie rod end

[kolle_hond]

Hey everyone,
I took off my spindles to try and figure out how to re-do the disc brake conversion that got stolen off my truck, and have now put them back on.
The issue is that I have two pieces that won't fasten properly, I can get the nut back on up to a certain part, then the thread just spins around with the nut, not letting me fasten it any further.
Any idea how I can maybe clamp it with a vice grip or something in order to fasten them? I don't currently have the money to replace the parts and they are difficult to find here in South Africa.