Step 4 · Remove the Faucet Cartridge
With the handle removed, the top of the cartridge is exposed. You will see a packing nut or retaining bonnet threaded over it. Use channel-lock pliers or an adjustable wrench to grip this nut and turn it counter-clockwise to unthread it completely. Once the nut is removed, grasp the stem of the cartridge with the pliers and pull it straight up out of the faucet body. The cartridge may be snug, so a gentle wiggling motion may be necessary to free it. Pay close attention to its orientation (how it's aligned) before you fully remove it.