The first step in replacing a toilet and installing a new one is to inspect the stall area where the toilet will go. Look carefully at the water valve on the wall. See what kind of hose it has. Inspect the floor flange to make sure it is in good condition.
The next step is to understand the requirements for the new fixture. Measure the distance from the floor bolts to the back wall and record this dimension. If there isn't already a toilet in place measure from the center point of the drain.
Now its time for a trip to the home improvement center. There you will browse the different models of toilets. Make sure to get the advice of good sales person. Also make sure to select a model with the same rough in dimensions you measured on the drain.
The next step is to roll up your sleeves and wrestle out the old fixture. Un-do the two bolts holding the toilet to the floor. Turn off the water supply. Unscrew the hose. Then simply rock the toilet back and forth and it will come loose. Get a someone to help you lift the fixture at they are heavy.
The right place to dispose of an old toilet is the local refuse center. You may need to take the toilet apart to make it easy to carry out. That way it might also fit it in a small car.
Take the new fixture out of the box. Carefully review the instructions paying special attention to organize the parts that came with the toilet. Most toilets are nearly assembled but do have some loose parts.
To install the toilet, first place the wax gasket on the floor flange. Fit the floor bolts into the floor flange. Next position the toilet next to the flange and place it carefully over the bolts. Secure the nuts, and connect up the water supply
To test the toilet first turn on the water valve, located to the left of the toilet. You should hear the tank filling. Inspect the water line, tank, and floor for any potential leaks. Flush the toilet, and then inspect again for leaks.