After cleaning, make 2 copies of the chkn. (CHKN A, CHKN B)

In CHKN A, delete all actions from the actions tab.
Then delete all unused assets from the assets tab.

In CHKN B, delete all meshes from the meshes tab.
Then delete all unused assets from the assets tab.
Then use the PPE to change the parent PID to one belonging to a derivable accessory: viewtopic.php?f=179&t=10094