Start by turning off the water that runs to the toilet. Loosen the hex nut attaching the water line to the toilet valve. If water drips, wipe it up with a towel. Next, remove the mounting nuts. Remove the nut in the access hole using a socket set on the 12-inch extension. Remove the toilet by pulling it straight up from the mounting bolts. Put the toilet on the side, placing it on a soft surface.
Prevent odors from escaping the hole by covering the area with a towel or sheet. This will also help parts from accidentally falling in. Remove the gasket from toilet flange, and lift and twist it to break the seal. Next, clean the flange of any gasket stuck to the toilet. Place the gasket onto the flange using plumber's sealant. When you this is complete, remove the towel from the hole and place the toilet over the bolts.
Carefully lower the toilet over the bolts. Make sure the toilet is correctly seated so it is not placed crooked. Replace the caps onto the bolts. Once completed, reattach the water lines running to the toilet. Turn the water on and test the toilet by flushing the handle to assure there is no leakage.