Since you got a new track bar, simple enough to reattach. Once you have it on, adjusting it, you may have to remove it from the frame end. To center the axle after the new springs, measure the same location on both sides. Then adjust 1/2 that number, and recheck for centering. I had to get my steering a few twisty turns to get the front over enough to remount the track arm.
To get the springs installed, I didn't have to remove my track arm. I did have to disconnect the sway bar, and the lower shock mount from the axle to get it to drop far enough.
As for the ZJ arms, the TJ has adjustable lower mounts on the front axle. Once you break those, you can get out of alignment. I don't think it's necessary for the OME springs.