If the Change Activity (aka Change Task) has already made it to the Resolved state, as it is in the OOTB CN/CA workflow, no can do as far as I'm aware.
We currently have a workflow where the Auditor can choose rework on the entire Change Notice, but it doesn't use the Change Activity for the rework process. Instead, any rework from the Auditor goes to one person who then reassigns it as necessary. After rework is completed, it goes to that same person to either review it himself or to reassign the review process. Not very elegant, but it's the best we could come up with using some of the limitations in the Change Management workflows.
One thing I played around with previously is to move the Audit task into the Change Activity instead of having it in the Change Notice. If that were the case it would be easy to put in a rework link loop. The drawback, of course, in cases where there are multiple Change Activities the Auditor would get multiple reviews. This would depend upon your specific requirements.
I've heard that Change Notices can be iterated, but I'm not sure if the Change Activity can be or if doing so would then fire off the CA and how that might interact with the CN and any synchronize robots.