My brother has a 58 plate S3 and only recently it has started not to idle smoothly, it is as if you keep gently pressing the accelerator and releasing it and the revs keep going up and down slightly.

This does not happen when driving, only when idling

Am I right in saying this might be the Idle Control Valve just needing to be cleaned?

Is this an easy thing to access and clean? Or best taking it to a mechanic?