How to delete unused equations and cut-list (ghosts in part file)

I have a part with cut-list feature. I try to delete it but without success. The reason of this is old sheet metal references (see equations).

I try to delete equations but without succes too.

Is it possible to purge unused equations and features from part.

Please see file (sw2017 sp1)

SolidworksDrawings And Detailing