How to Implement a Man in the Middle After Creating an Evil Twin

Hi,

I am able to set up an evil twin using the aircrack suite and bridge utils.

What I'm trying to achieve now is a Man in the middle (using ettercap) between the real Access point and my evil twin and trick the real AP to think my Evil twin is the client connected to me.

Generally speaking this should be a Man in the middle Channel Based.

The picture attached shows the scenario I'm trying to achieve, the missing step is the second one.

Do you guys have any suggestions on how to do this?