1. Trim the drain pipe in the floor to the height recommended by the manufacturer (usually near or slightly above floor level). Stuff a rag into the drain pipe, and leave it in until you are ready to make the drain connections.

2. Prepare the shower drain piece as directed by the manufacturer, and attach it to the drain opening in the shower base. Tighten locknut securely onto drain tailpiece to ensure a waterproof fit.

3. Mix a batch of dry-set mortar, then apply a 1" layer to the subfloor, covering the shower base area. Mortar stabilizes and levels the shower base.

4. Apply soap to the outside of the drain pipe in the floor, and to the inside of the rubber gasket in the drain tailpiece. Set the shower base onto the drain pipe, and press down slowly until the rubber gasket in the drain tailpiece fits snugly over the drain pipe.

5. Press the shower base down into the dry-set mortar, carefully adjusting it so it is level. If directed by manufacturer, anchor the shower base with screws driven through the edge flanges and into the wall studs. Let mortar dry for 6 to 8 hours.