There are many steps you must follow in order to fix a leaky faucet.
First you must locate where the leak is. Faucets are sold in many different types and models, but the most common fall into just two types: washer faucets and washer-less faucets. Washer type faucets work with a rubber washer that closes onto a medal seat. When the washer begins to wear out, it will cause a leak in the rubber washer. It is possible to just tighten the washer, but the best thing to do would be to replace it. In order to replace the washer, the first thing you need to do is turn off the water, and the hot water heater. This will hopefully reduce any risk off hurting yourself.
You first start by taking off the handle to the faucet. Once off, you will need to un-screw the cap, you need to take off the handle and work your way down to the stem nut and packing nut. Once those are off you can test the stem and threads to see if they are causing the leak. You can examine the stem; you will be able to tell if it is causing the leak by how bad it is worn and corroded. Now locate the washer, which is at the lower end of the stem and held in place by a screw, if the washer is flat or has a groove worn in it, it needs to be replaced. You should take this washer into the store and have it matched at the hardware store to make sure you get the right size. If the faucet continues to leak, the problem is probably being caused by a bad seat. This can be determined by using a seat-dressing tool. In order to replace the faucet seat, you will need a faucet seat wrench, which comes in a combination of sizes to fit most faucet seats. To get it off, turn the washer seat counterclockwise to loosen it. Once off, you will need to add rubber sealant to the pipes surrounding this area which will hopefully reduce the chances of another leak due to this problem. Afterwards you will need to put the washer back on, and then screw everything back in the opposite order you took it off before. This should fix any leaks you are having in your faucet.
