Remove all dirt and debris from the showering alcove. Measure the shower alcove with a tape measure and then measure the liner to ensure it fits properly. If the liner is not sized properly, you must order a properly sized liner for your shower.
Install a length of PVC drain pipe through the bottom of the floor in the drain hole so the top of the pipe sticks up through the drain hole in the liner. Check the floor with a level to ensure it is level. Apply a layer of cement to areas that fall below the level mark with a trowel and fill the bottom side of the pan with cement.
Brush adhesive PVC cement over the drain and set the liner into the alcove with the sides flush against the shower walls and over the drain pipe. Push each edge flat against the wall with your hands and make sure both sides rest evenly on the wall framing. If you have an exposed drain pipe without sub flooring access, brush the cement on the drain pipe stub and then install the liner.
Let the pan liner and cement dry in place and do not walk on the pan liner. Apply mortar over the seam between the wall and pan liner and let this dry.