Use a metal spatula and start peeling off the Cer-Deck from a corner of the item/mat.
Pull gradually to avoid tearing the Cer-Deck item/mat.
Once the entire mat is removed, there will be a small amount of double-sided adhesive film left on the surface.
Soak with mineral spirits for 10 minutes, then remove the residue with a spatula. Once the double-sided adhesive film residue is removed, use acetone to remove the mineral spirits.