Turn the saddle valve on the water line clockwise to turn off the water supply to the water filter.
Press the vent buttons on the top of both sides of the filter to relieve the pressure in the filters.
Remove the right sump pump from the water filter by twisting 1/8th of a turn counterclockwise and then lowering. Keep the sump pump in below the CF2 cartridge to catch any water that may fall from the CF2 cartridge.
Twist the CF2 cartridge counterclockwise under the right sump pump and then pull down to remove.
Place both the sump pump and CF2 cartridge in the sink to drain any remaining water.
Remove the cartridge adapter if you would like to clean the M1 ceramic cartridge, which should be cleaned once every 12 months. The cartridge adapter is the piece on which the sump pump connects. To remove, unscrew it from the head boss.
Wipe clean both the cartridge and the head boss, then screw the cartridge back onto the head boss.
Insert a new CF2 cartridge into the housing and then twist clockwise to secure.
Replace the right sump pump by placing it into position over the new CF2 cartridge, then twisting clockwise.
Turn on the saddle valve and then turn on the faucet to allow any trapped air to escape from the system.