How to remove the ceramic disc cartridge from faucet: (note, these step are demonstrated in the video above):
Turn off the hot and cold water supply to your faucet. To do this, locate the stop valves underneath the sink. There will be one for the hot water and one for the cold water. Turn in a clockwise motion until tight. While you have now turned off the water supply, there will still be a small amount of water still sitting in your pipes and faucet. Turn the handle to the full "On" position to drain the remaining water.
Remove the decorative silicone cap at the back of the handle. This can easily be removed with a toothpick, paper clip or other small pointed item. Make sure to keep this is a safe place while you work as you will need to replace it later.
A small Allen wrench was sent with your faucet. Use this to loosen the set screw at the back of the handle. If the supplied Allen wrench has been misplaced, any 2.5 mm Allen wrench will work. Important – make sure that you simply loosen the set screw – do not remove it completely. If completely removed, replacement will be much more difficult.
Remove the handle. Set aside.
Unscrew the decorative cap. You should be able to remove this by hand. If it has been tightened excessively, you can use a wrench to loosen, but make sure to first cover the faucet with a protective cloth or it will scratch. Once you have loosened the cap, remove it the remaining way by hand. Set aside.
Remove the brass retaining nut. You will have to loosen it first with an adjustable wrench. While you don’t have to worry about scratching the retaining ring as it doesn’t show, you need to take care not to scratch the faucet finish while working. Once the retaining nut is loosened, remove it by hand and set aside.
Remove the ceramic disc cartridge by simply grabbing from the end and pulling upwards. You may have to wiggle the cartridge from side to side a few times to loosen first, then pull up.
How to replace the ceramic Disc cartridge: (Note: these steps are demonstrated in the video above).
Look inside the faucet cavity and you will see 2 larger holes and 2 smaller holes. Line up the 2 larger holes on the bottom of the cartridge with the larger holes in the faucet cavity and insert the cartridge. Gently turn the cartridge until the holes line up precisely and the cartridge properly seats. You will know that the cartridge is in the correct position with you feel and see it lower slightly into the faucet cavity and you can no longer rotate it.
Make sure to align the top of the cartridge so that it points straight ahead because this is what positions your handle.
Replace the brass retaining nut by first hand tightening and then using an adjustable wrench to tighten completely. Note: Tighten only until you feel no resistance. Do not over tighten or cross thread.
Replace the decorative cap by hand tightening.
Replace the handle and tighten the set screw at the back of the handle.
Replace the decorative silicone cap to cover the set screw.