Many first-time guitar owners have their strings changed—and get all other maintenance work done—by a professional or at a local shop. As you become more experienced, however, it’s often useful to learn how to do it yourself. For one thing, it’ll save you a lot of time and money. For another, you want to be able to feel your way around it and know when it’s time for a new set of strings.
You can change your strings using just a pair of pliers. Some people use a tuning fork or tuning winder, which you may find useful if you’re new to the craft but aren’t really imperative. Always start by removing the top three strings—the bass strings—so that some tension is left on the guitar to help you finish the job. Use the pliers to loosen and then pull out the pegs holding the string to the surface.
Once the strings are off, clean the area underneath using a good-quality guitar polish. Use a soft, smooth cloth to avoid scratching the surface. Make sure to clean not just the fret board and the wood under the strings, but also the head, neck, and the space next to the bridge. Many people just do a quick swipe over these areas, but they actually tend to collect a lot of dust and they can be hard to clean if there’s too much buildup.
When installing the new strings, start with the bass strings again and then move down. Starting with the E, place the string with the nut end in the peg hole, then follow up with the A and the D. Then replace the peg and push it down to hold the string in place. Next, thread the other end of the string through the peg tuner or machine head, keeping it just loose enough to wrap twice or thrice around the tuner. Place a finger on the part being tuned to keep it flat until the string has tightened enough. You may want to use a hand-held winder to speed things up at this step.
Finally, wind up the string, starting over the threaded end to keep it in place. Make sure you’ve strung inside the peg tuners. Do the same with the next three strings, starting with the G and followed by the B and the E. Pluck the strings individually to make sure they’re properly tuned, using your other tools if necessary, and your guitar is good as new!