Once the track bar is off, there is nothing to prevent the chassis from moving laterally relative to the wheels and axle. You should do this parked on a flat, level surface. Use a plumb line dropped from each fender (or flare, if you still have 'em) and something like a bottle or screw jack set at an angle to push the chassis laterally until both sides are the same.
Then bolt up the axle end of the new track bar, and adjust the upper end until it drops into place without causing the chassis to move off center.
Yeah.... thanks Eagle! haha
I didn't know if the LCAs or anything else had to be disconnected for that thing to shift. My axle is a good inch off to the drivers side. It goes on tomorrow. Thanks for the info guys.