Seperating IFR/VFR in Class

[learnatc]

Hello

How would an aerodrome controller seperate IFR from VFR (and vice versa) in an ATZ environment in Class C Airspace?

For example if the controller had aircraft in the circuit (under VFR) - and inbounds on the ILS (under IFR) - How would he ensure the separation between the two?

Thanks