Copy and paste below. This is what I used and easy.
Credit to Overlander (mark kellgren)
http://www.defendersource.com/forum/f14/wheel-alignment-50225.html
This is exactly how I did mine after researching different methods. I found this one on youtube, and it worked like a charm, easy to do and is damn near spot on.
you use virtually any string on spool that you can pull tight (kite string, yard string, etc). put one lift jack in front of each tire a couple feet in front of it. Tie the string to one jack at hub height, then run the string along the front and rear hubs, around the back, and then along the hubs on the opposite side. Tie the string to the other jack. Adjust both jacks left or right so that the string on each side touches the front sidewall on the front tire for that side. If you parked straight, then your wheels are aligned when you see the string on each side of the D touch both front and rear sidewalls on each tire (4x touches per side). If your front tires are not aligned, then align the passenger side (where the tie rod and drag link both connect) by turning the steering wheel until the string touches both front and rear sidewall on the right front tire. On the opposite drag (driver) side, you should only see one side wall touch (either front or rear sidewall). Adjust the tie rod out or in until the string touches both. Recheck the passenger side alignment. when string hits both fronts twice, you are aligned.