Replacing the jar rings on your Diatom Filter need not be a hard job. To replace the jar ring it is not necessary to remove the Main Casting from the P-1 Motor. Remove the old jar ring from the casting. Heat the new jar ring to about 150 degrees by running hot tap water over it. Hold the jar ring against the side of the main casting (fig. 1). With the jar ring still hot you will be able to force it over the rim of the casting into its proper position (fig. 2 & fig. 3).