Drain all the water by turning off the valve under the sink and turning the faucet on until the water stops running.
Loosen all the screws using hex wrench and remove the handle. If you can’t find the screws under the handle, look under the counter below the faucet.
Lift off the cap to access the cartridge then loosen by using groove-joint. Then lift off the cartridge with your hands or groove-joint.
Clean the seals and seal seat area using an old toothbrush. If you can’t remove the sediment and seal build up, it is suggested to replace this part. Set a side until parts are dry.
Next, remove the o-ring from the inside of the faucet body and coat with silicone grease then re-install.
Reinsert the cartridge inside the faucet body and tighten with groove-joint pliers. Same step for the decorative cap, tighten using your hand to avoid any form of damage.
Reinstall handle, tighten using Allen wrench.