The part that fails in many faucets is called the stem, which usually has rubber or fiber O-rings. washers, and/or turn-seals. Danco company that makes a lot of faucet parts. I found that inside the little bubble pack holding their products at the hardware store there are1-2-3… step-wise instructions on how to replace. I bet other companies are smart enough to do that and also have instructions on their company web sites. Ron