Yes, I searched.

Yes, I have a good reason. I inherited a design from someone else, who originally modeled a part as sheet metal. At some point, for whatever reason, he added thickness to represent a thick metal plate.  All was fine until I needed to add a cut partway through the thickness.  This doesn't work in sheet metal.  I tried the obvious things, like deleting the sheet metal feature.  But that deletes everything.

There are hundreds of threads on converting solid to sheet metal.  I can't find one that answers this simple question.  How to go back?

Thanks in advance,

John.