Flush the tank to remove all water from the tank.

Disconnect the supply from the tank.

Remove bolt caps or bolt covers from where the toilet bolts to the bathroom floor.

Remove bolts from the floor flange. When you lift the toilet up, you'll see a metal or plastic flange. If the toilet has been there for a long time the bolts may not pull out of the flange easily. In this case you may have to use a small hacksaw to cut the bolt below the nut.

Put newspaper or an old towel on the floor so you can place the old toilet on it. Lift the toilet off the flange.

Take the new bowl (assuming this is a two-piece toilet) and turn it upside down. Position the wax ring on the horn of the outlet. Install new solid brass flange bolts, mount them and position them on the centerline on either side of the outlet.

Push the bowl down over the bolts and seal the outlet. The wax will squeeze down and seal.

Put the new bolts, washers and bolt caps on. You may have to trim the bolt with a hacksaw.

Once the bolts are secure, mount the tank.

Make sure the gasket between the tank and toilet is in place. Then position the tank on the bowl. Run bolts through the tank and secure. Don't over tighten (the tank can crack).

Hook up the water supply line.

Connect the supply to the line on the bottom of the tank.

Turn on the water.

Let the tank fill.

Flush once or twice to make sure the water control is properly adjusted.

Put the tank lid on.

Enjoy.