What is the process for replacing a Symmons shower valve cartridge?

To replace a Symmons shower valve cartridge, first turn off the water supply to the shower. Remove the handle and trim plate to access the cartridge. Use a cartridge puller tool to carefully remove the old cartridge. Insert the new cartridge in the same position and reassemble the handle and trim plate. Turn the water supply back on and test the shower to ensure the new cartridge is working properly.