To install a shower pan, place the shower pan over the existing drain to ensure the drains fit properly, and set the pan aside. Install the drain flange and rubber gasket, set the shower pan into place, and apply caulking to the drain flange. Install the shower drain cover, check the shower pan to ensure it is level, and drill holes through the pan at each stud. Use galvanized nails to attach the shower pan to the surrounding wall studs.
To install the drain flange, dry fit the flange into the drain pipe to ensure it fits, apply primer and pipe cement to the bottom of the flange where it joins to the drain pipe, and place the flange on the drain pipe. Allow the adhesive to set for the recommended amount of time.
Place the rubber gasket on top of the flange, set the shower pan into place, and apply caulk to the drain flange where the flange meets the shower pan. Immediately place the drain body in the shower pan to ensure the caulk seals the drain connection properly, and secure the drain body using the provided screws.
Use shims to level the shower pan before nailing it to the wall if necessary, and check the shower pan for leaks after installing it.