What to do with old alternator?

[Getriebe Guy]

I just replaced a bad 90A alternator with a new one I bought from tdiparts. I didn't pay core and now I have an unworking old core alternator. Any tips on how to get somebody to pay me for the old one?

 

[DPM]

repair it?

 

[Getriebe Guy]

I'll see if the auto electric shop near me can tell me where to get it rebuilt for cheap then I would have a backup.