Using your shower base as a guide, determine where the drain pipe should terminate. Allow between 3/4- and 1-inch clearance. Cut the drain pipe to your measurement.
The actual drain can be installed to the floor of the shower using either silicone caulk or plumber's putty applied to the drain ring. Push the assembly through the drain hole, and tighten the nut securely with the rubber washer and compression gasket in place. Remove any excess caulk or putty.
Line up the drain with the shower base, then move the rubber washer into place over the drain collar. If necessary, use a rubber mallet or screwdriver to seat the drain properly. Using the included tool, tighten the compression gasket from inside the drain.
Use silicone caulk to seal all gaps around the shower base. Wipe away any excess putty or caulk after final tightening. Wait at least 24 hours for all caulk to dry and seal to properly seat.