AD Import - Dept & Site Refresh

AD Import - Dept & Site Refresh

Hi,

We've just a big update of the department and office fields in AD.

We now need to do a been clean up of Department and Site records in Service Desk.

What is the best way to do this?

I'm going to guess that each current record in those tables has a unique id, so I can't just do a full clear down of all departments and sites and then run the import from AD?

Is there a way, or do I need to manually delete the departments/sites no longer required?

Many thanks
Lisa