How to tell tenants about new owner?

[Randall Williams]

I'm buying a duplex in my town. At inspection, the tenants in one unit didn't know who we were or what was going on. They figured that they'd be evicted when the property sold. 

We close in a month. I'd like both tenants to stay on. The current owner's agent is saying no to any communication with them about the sale until closing. 

Any suggestions on how to ease the transition for the tenants?

Thanks, 

Randall