Re-Centering Your Steering Wheel
1. With your tires pointing as straight as possible (leave your steering wheel rotated) and your tires on the ground, loosen the bolts on your drag link turnbuckle using a 15mm deep socket or wrench.
2. Grab the turnbuckle with your hand and rotate it a little bit at a time. Check your steering wheel periodically while doing this until it appears to be centered again.
3. Try to make sure that the bolts are pointing away from the track bar (rotate just the bolt sleeve and not the turnbuckle itself if necessary) and then tighten up the turnbuckle bolts.
4. Take your Jeep out for a test ride and determine if you need to make any other adjustments. It may take a few times to get it right but at least it is easy to do.
See the link for some pictures: http://www.4x4xplor.com/alignment.html