There are a few ways of tuning the guitar. The easiest way is using a clip-on tuner which can be bought from any guitar shop. This kind of tuner is preferred as it is clipped onto the guitar and tunes by vibration. Hence, it is more accurate as compared to other kinds of guitar tuners.
a) Clip the tuner to the headstock of the guitar
b) Switch on the tuner, the screen lights up.
c) Start by plucking the bottom E string, a needle appears on the screen.
d) Turn the corresponding tuning peg and the needle will move closer to the center of the screen.
f) Do likewise for the rest of the strings.