yeah, the drag link ends to the pitman arm on the bottom of the steering box.
They are opposing threads, loosen the safety nuts and turn the actual drag link. As you turn, it will make it longer and shorter causing your pitman arm to move slightly, thus straightening the steering wheel, or causing it to be more off center in which you turn the opposite way
I have to do this adjustment every time I rotate my tires. I cannot stand my wheel being off center. As well, usually you have to do it at least twice. You can have someone watch the wheel or turn the link and get is dead on. But the first time you drive you might find your tires were a little off center. Drive it straight again and park w/the tires centered but the wheel crooked and re-adjust until your cool w/the position.
I also use grease on my threads for the drag link to keep it from rusting up on me. Its a pain when the threads are all crappy on the link ends and it does not want to turn easy.