Sit straight in Easy Pose.

Eyes: Meditate at the Brow Point.

Mantra: Produce the five primal sounds (panj shabd):

S, T, N, M, A, in the original word form:
SAA: Infinity, cosmos, beginning
TAA: Life, existence
NAA: Death, change, transformation
MAA: Rebirth

Each repetition of the entire mantra takes 3 to 4 seconds.
This is the cycle of Creation. From the Infinite comes life
and individual existence. From life comes death or
change. From death comes the rebirth of consciousnes to
the joy of the Infinite through which compassion leads
back to life.

Mudra: This mantra can be done in many different
mudras. Most common is to begin in Gyan Mudra. The
elbows are straight while chanting, and the mudra
changes as each fingertip touches in turn the tip of the
thumb with firm pressure.

On SAA, touch the first (Jupiter) finger
On TAA, touch the second (Saturn) finger
On NAA, touch the third (Sun) finger
On MAA, touch the fourth (Mercury) finger

Chant in three languages of consicousness:

Human: normal or loud voice (the world)
Lovers: strong whisper (longing to belong)
Divine: mentally; silent (Infinity)

Time: Begin the kriya in a normal voice for 5 minutes;
then whisper for 5 minutes; then go deep into the sound,
vibrating silently for 10 minutes. Then come back to a
whisper for 5 minutes, then aloud for 5 minutes. The
duration of the meditation may vary, as long as the
proportion of loud, whisper, silent, whisper, loud is
maintained.

[Source: Yogi Bhajan, KRI]