Transfer the cutouts to the back of the first copper sheet. Do this by laying the plywood on top of the backside of the copper sheet and tracing the holes with a pencil.
Cut the marked areas using a tool with a carbarundum cutting wheel. Be sure to wear safety goggles when cutting metal.
Apply construction adhesive to the back side of the plywood, and stick the plywood to the wall.
Apply construction adhesive to the back of the copper backsplash as well -- a dollop in each square -- and set it to the wall. Overlap the next piece about 1/2" so the pattern will match.
Use the special copper nails to finish off the backsplash. Drill pilot holes through the copper for the nails. Be careful nailing because copper is soft and will dent easily.
To trim the copper backsplash, measure and cut pieces of trim and mold cover, and nail them into place using an impulse finish nailer and 1-1/2" nails.