Turn off the water supply to the toilet
Flush the toilet to empty the tank and bowl
Sponge out any remaining water from the tank and bowl
Disconnect the water supply line
Remove the nuts from the toilet bolts at the base
Rock the toilet gently to break the wax seal
Lift the toilet straight up and remove it
Scrape off the old wax ring from the flange
Inspect the flange and repair it if needed
Place a new wax ring or seal on the flange or toilet
Set the new toilet carefully onto the flange bolts
Press the toilet down evenly to seal it
Install and tighten the nuts on the bolts
Reconnect the water supply line
Turn on the water supply
Let the tank fill and check for leaks
Flush the toilet several times to confirm proper operation
Caulk around the base if desired, leaving the back unsealed