The drag link is the bar that goes from the pitman arm to the passanger side wheel (there should be 2 slanted bars if you look at the Jeep from the front, one is the draglink, and the other, which should attach to the frame, is the trackbar if you still have it on). The drag link should have 2 nuts at each end (threaded to the bar itself); loosen them (one has the backwards thread, so keep that in mind!) and then using a pipe wrench, turn the middle. This will cause the draglink to extend or contract, which will center the wheel to the correct place. Once the steering wheel is centered, re-tighten the nuts. You are all done.