If your toilet, or  water closet, is old or in need have repair, you may find it's cheaper to  install a new one than to patch up the existing one, especially if you do the  job yourself. Installing a new toilet is actually a rather simple plumbing  procedure that can be accomplished in just a few steps. To install the new  toilet, you'll need a new toilet gasket and two 5/16-inch bolts to mount the  bowl to the floor flange, but most of the required parts will be included with  the new toilet. 
                                 
When removing the old toilet, shut off the water supply to the tank and flush  the toilet. Use a bucket or cloth to remove any leftover water in the tank and  bowl. Using a pair of pliers or small pipe wrench, remove the nut connecting  the water line to the ball cock valve at the bottom, left side of the tank.  
                                  
                                 
                                
  | 
                                | 
                               |