Non leased Occupant won't leave

[Gregory Wyatt]

Hello!  I recently purchased a few condos in a complex, and have a situation that I inherited.  The person that's responsible for the lease originally added another individual as an 'occupant'. The leasee is in good standing, but now wants the 'occupant' out of her condo.  The occupant is saying that she cannot be forced out without a 30 day written notice. 

I'm not a lawyer, and I was wondering:  Is it my responsibility to give the occupant a 30 day notice, or is it the responsibility of the tenant?  Is a 30 day notice even warranted in this situation, or does the leasee have the right to just tell the occupant to leave?

I appreciate all comments.

Greg