1. First, turn off and disconnect the water supply. Once the water is shut off, flush away all the water in the tank.
2. Unbolt the tank from the bowl and use a wrench to remove the nut and plastic retaining nut that holds the flush valve in place. Remove the old flush valve.
3. Check and adjust the height of the overflow pipe.
4. Install the new flush valve by assembling the tank-to-bowl gasket onto the threaded end of the flush valve and install the valve in the hole at the bottom of the tank. Use the wrench to tighten the retaining nut.
5. Connect the flapper chain to the tank lever arm and attach the existing refill tube to the overflow pipe.
7. Reconnect the tank to the bowl and turn the water supply back on. Flush the toilet several times to make sure that it is working properly.
Fluidmaster's Toilet Flush Valve, as well as other bathroom plumbing specialties, can be found at www.supplyhouse.com