On the drag link (this is the bar that goes from the pitman arm down to the tie rod) there is an adjusting sleeve. With the tires pointing straight ahead you will want to make sure the steering wheel is unlocked and then crank that sleeve one way or the other until the wheel is straight. Won't take too many turns, maybe 15 or so I would guess.
Is your new track bar adjustable? Make sure if it is adjustable that you have centered your axle with the correct adjustment on the track bar first.
Once you have centered your axle, then you can adjust your steering wheel with the procedure listed above by adjusting your sleeve on your drag link.
It will take a few adjustments to get it just right, but keep playing with it. One revolution of the adjusting sleeve makes a big difference (I would doubt that you would need to turn it more than twice to adjust for a 45 degree off wheel), so it helps to have someone sitting in the drivers seat and watching (but not holding onto the wheel). Then take it for a test drive and see how it drives. Readjust it if necessary.
Tho one thing I would caution you on is that centering your wheel is not an "alignment".