Lay tarps in a bathtub, over the floor and fixtures in the bathroom. Remove items hanging on the walls.
Slice through the caulking between the cultured marble panels and at the edges with a utility knife. Run the knife down the length of the caulk several times while pressing down on the knife until the blade cuts through the caulk and reaches the substrate.
Put on safety goggles, work gloves and a dust mask.
Wedge a thin pry bar under the edge of the cultured marble tub surround. If the adhesive bonds the cultured marble tightly to the substrate, hold the end of the pry bar at a low angle to the wall with the tip of the pry bar resting at the point at which the panel meets the wall. Strike the top of the pry bar with a hammer to wedge it under the cultured marble.
Press and pull the bar to pry the cultured marble away from the substrate. Continue to wedge the pry bar behind the cultured marble, strike the pry bar with the hammer and pry the panel off the surface until no cultured marble remains around the bathtub.