Most cars and trucks today have what is called a serpentine belt which runs most accessories.They are very dependable and usually easy to replace. To decide if your belt needs replacing, simply look at the grooved side of the belt to see if it is cracking badly. A couple of cracks every 3 inches is normal, but if you see cracks every 1-2 inches I would recommend that you replace it. On most cars and trucks the procedure is basically the same. First off, get the correct belt by bringing your cars VIN number to the parts store(located on your cars dashboard) the parts store may need it. If there are two choices, get them both so you can complete the repair. Once you have the correct belt, take a minute to review how the belt runs across the pulleys and also check to see if your car/ truck has a underhood diagram of belt routing in case you need it. In most cases you will need a socket wrench or breaker bar with either a 3/8" and /or 1/2" head on it and possibly a short extension. Some models may require a wrench of these similar sizes.Now that you are ready to go to work, you will need to find the spring loaded tensioner which is generally located near the top of the belt path; it usually has a shinny pulley on it. Look at the tensioner and insert the tool into it and apply opposing pressure to release the belt.Now, simply install the new belt making sure it fits into the grooves on all the pulleys. Start the car to check it and you are done and you saved yourelf some money!