There comes a time when you need to attend to the tie rod ends on your Ford Focus, especially when it doesn't track straight, and does not improve after an alignment. Fortunately, the amateur mechanic can replace the tie rod ends in a day.
Purchase tie rod ends meant specifically for your Ford Focus, because they vary from model year to model year. These tie rod ends come with a nut as well as a cotter pin (a glorified bobby pin).
Loosen the front tires' lug nuts with a lug nut wrench, but don't remove the tires. Jack up the Ford Focus, then secure it with some jack stands and remove the tires.
Use a wrench to loosen and remove the retaining nut of the tie rod end.
Separate the tie rod ends and the wheel knuckles with a ball joint press, then wrap the ball joint seals in cloth to protect them. Mark the position of the tie rod ends on the threaded portion of the tie rod. Chalk or paint works well.
Unscrew the tie rod ends.
Screw on the new tie rod ends to the mark you made on the threaded portion, then tighten the new nuts that came with the tie rod end to 45 foot pounds. Slip in the cotter pin, if your tie rod end comes with one.
Repeat Sections 1 and 2 for the other tie rod end, then put back on the wheels, and tighten the lug nuts to 94 foot pounds.
Get your Ford Focus aligned.