How do you replace a tie rod on a 1996 Ford Thunderbird LX?

Take it off then put it back on.

Get a Haynes or Chilton book on the car.

BUT, if they still show using a 'separator' to remove the outer tie rod end from spindle DO NOT do that! Instead:

Two Heavy hammers; Run the nut out to the end of the pin, hold one of the hammers behind the spindle arm boss, then pound the other side of the boss. This 'squeezes' the taper pin loose and does not tear up the dust shield on the outer tie rod end. NEVER USE a SEPARATOR ON ANYTHING, Even ball joints can be separated that way.