if you are talking the steering knuckle about mid way down the steering shaft. It is not hard to replace yourself. If you can get it aftermarket cheaper then I would do that. When replacing it the biggest thing to remember is set it where you can get to all the nuts and bolts. Mark it with tape grease pencil or something you can see. Lock the steering wheel into place. Then take out the knuckle and replace. I have done a few over the years and they are not hard to do.
They really are pretty easy to do just take your time and make sure nothing moves or you will need an alignment and someone to rest the steering.