how do I delete or merge duplicate records automatically?

After im****ting 2000+ records into my CRM 4.0 database, I need to remove
the 
duplicates. I created a Duplicate Detection Job and then was able to view
all 
of the duplicates, however I would like to be able to make all of the
records 
inactive automatically without having to go through all the pages of 
duplicates.  Do I have to do this manually or can I not choose to run a
mass 
delete or merge job?

I read this can be done with a workflow but after looking at workflows I 
can't see any obvious way of how to configure it?  

Thanks in advance for any replies!