How do you replace a cartridge in the valve body of a faucet?

To replace a cartridge in the valve body of a faucet, first, turn off the water supply and open the faucet to relieve any pressure. Remove the handle by unscrewing any screws or using a flathead screwdriver to gently pry it off. Then, use pliers to pull out the old cartridge from the valve body and insert the new cartridge, ensuring it is properly aligned. Finally, reassemble the faucet by replacing the handle and turning the water supply back on to check for leaks.