Using these D'Addario EJ88C ukulele strings is easy. First, remove the old strings from your concert ukulele. Then, thread the new strings through the tuning pegs and bridge, following the standard GCEA tuning. Turn the tuning pegs slowly to adjust the pitch until you get the right note. When it comes to maintenance, keep your ukulele in a dry and cool place to prevent the strings from rusting or losing their elasticity. Avoid touching the strings with dirty hands as it can affect their tone. If you notice any signs of wear, such as fraying or loss of sound quality, it's time to replace the strings.