[XCNuse]

Some of the AutoX guys have.
Likely any shop that can do any suspension work that has a 50+ ton press can do it if you take the arms to them.

Supposedly not hard.

But if that's the case, I'm not sure how significant the price savings would be (none at all), if you're just doing the ball joint, as I'm sure the inner bushes really need replacing as well.
After labor costs for the shop, I'm sure it actually costs MORE to do it like that, than getting new arms with all new bushes in the first place.

 

[XCNuse]

This post is not directed towards OP, but on the topic of this for anyone to see in the future.

Labor wise it makes more sense, time wise it makes more sense.

Cost is the only down-side, and even then it may not be all that much.

If you're going to do JUST the ball joint, why aren't you doing the other bushes? Because you should be! And if that's the case, how much money are you really saving by getting the other sets of bushes and the ball joints? Probably a fair amount. Okay. How about when it comes to the time it will take yourself, or what a shop will charge to remove them? You'll likely end up only saving $50, but it will also take several times as long, if not days longer.
Vs an immediate drop out, drop in.