IF you're thinking of the front tie rods, then Larry said it. They are generally easy to replace and a DIY.
IF you're thinking of the rear tie rods, there are bushings that go to the subframe. The rarely go bad, and if they do, replace the entire part. MB does sell the bushings separate but the time or tools involved are not worth it IMHO.
Alignment is required & the dealers generally do it best.