To use these D'Addario EXL110+ guitar strings, first, loosen the old strings on your guitar and remove them. Then, insert the new strings through the bridge and the tuning pegs. Tune the strings to the correct pitch. When you're playing, avoid using excessive force as it might damage the strings. For maintenance, wipe the strings with a clean cloth after each use to remove sweat and dirt. This will help keep the strings in good condition and extend their lifespan. Store the extra strings in a dry place to prevent rusting.