I've been down this path before and have tried various options....
but the easiest way is to create SM volumes....
These are the steps I use:
create _SM volume on the new AGGR
creat SM relationship to this new _SM volume
Qisece the SM relationship
Breat off the Mirror relationship
Take the original volume offline
Delete the original volume
Rename the _SM volume to the original name
Create new share for the volume.
hope this helps.