Actually what you do is unwind or release tension on the bars by loosening the adjusting bolt. Follow the bar to it's rear anchor point, and you'll find it connected to a crossmember under the cab via adjustable arms (as shown below):
[IMG]http://img168.imageshack.us/img168/2033/tbaradjust001.jpg[/IMG]Simply unscrew the adjusting bolts and the front will drop. Use caution however in how much you lower the front. The further it drops, the more the arms hang down at the rear. On severely lowered trucks the arms hang below the scrub line and become a road hazard.
