They can be rebuilt. But depending on what is hosed up I would send it off to a rebuilder who can set it up and get it balanced properly. Or just swap it for a rebuilt one. Depends on your budget and expertise. These kind of things are above my pay grade and comfort level. Not that you couldn't DIY. But I don't recommend it.

PM me as I have a rebuilt turbo I might part with. I would need the core though.