Using these D'Addario XT phosphor bronze acoustic guitar strings is easy. First, make sure your guitar is in a stable position. Loosen the old strings and remove them one by one. Then, start threading the new strings through the bridge and up to the tuning pegs. Tune the strings to the right pitch. When you're playing, be gentle at first to let the strings settle. As for maintenance, after each play session, use a clean, dry cloth to wipe the strings. This helps to remove dirt and sweat, which can speed up corrosion. Store your guitar in a cool, dry place to keep the strings in good condition. If you notice any signs of excessive wear or corrosion, it's time to replace the strings.