1. Let filtered water free flow from the tap by lifting the black  lever to an upright position. ^

2.  Now shut off stopcock or isolation valve, situated under the sink.  Once the stopcock or isolation valve is shut off, then the free flow water from your tap will stop running.

3.  Now you can unscrew both under sink housings (from right to left) and take out the cartridges.  Rinse out the housings thoroughly and place the new cartridges in them.  The sediment cartridge (pre filter) on the inlet side and the carbon cartridge (post filter) on the outlet side.

4.  Ensure that the black “O” ring is properly seated in the groove – petroleum jelly (Vaseline) may be used to lubricate the “O” ring if required – this will help prevent leaking.   Make sure you tighten the housings hand tight (housing spanner may be required) in a clockwise direction. 'Do not over-tighten the housing'

5.  Turn the stopcock or tap back on.

6. This will start free flowing water from faucet.  Leave it on for 1 to 2 minutes to flush the system.

7.  There may be air bubbles (a milky look) in the water the first few times you use it.  It is only air and will go away in a short time.

Enjoy Your Pure Water!