Normally EV comp is engaged/adjusted simply pressing the +/- button on the back. Note that you are normally adjusting the shutter speed when you modify the EV value, not the aperture.
Manual is directly changing the shutter speed or aperture yourself. I am simply clarifying which method is used to achieve the F stop adjustment. Thus it's a combination of shutter speed and aperture modifications, not just shutter speed.
I've tried EV comp only and had mixed results sometimes. Need to look at that a bit more....
Regards,
Marc