Mahashodhas Nyasa a very essential ritual for tantra sadhna

Nyasa or touching the various parts of the body with mantras is an integral part of Tantra. Various types of worships have different nyasas & mantras. Apart from the Tantrik significance, the touching of the various parts of the body activates and purifies the various nadis or nerve centers of the body. The Maha-shodhanyasa is a highly effective one and it is said that if you perform it even without knowing the significance, it bestows a lot of spiritual benifits.
The Sodha Nyasa (sixfold nyasa), which is part of the daily worship of Tripurasundari, is here for the first time translated into English, from the work called Nityotsava, itself a commentary on the famous Kalpasutras of Parashuram.
Parashurama was a brahmana initiated by Lord Dattatreya into the worship of Shri Shri Mahatripurasundari Lalita Devi. The Kalpasutras provides a compendium for the worship of that Devi. Various forms of nyasa, which means ‘placing’, enter into this and all other forms of tantrika puja. The dialogue between Parashuram and Dattatreya is contained in the Tripura Rahasya, a wonderful work which is available in an English translation published by the Sri Ramana Ashram in Tiruvannamalai.
The Sodha Nyasa in which Devi outspreads as Ganeshas, planets, 27 nakshatras (asterisms), yoginis of the seven dhatus or bodily elements of ayurveda, sidereal zodiac, and sacred sites (pithas) is described in very many agamas such as Vamakeshvara Tantra, Gandharva Tantra, Jnanarnava, The 1,000 Names of Lalita, etc.. It is described in detail in the Yogini Hridaya, itself said to form the latter part of the Vamakeshvara Tantra.
The ritual centres the worshipper as one with She whose true nature is Chit or Consciousness Shakti. She is triple in Her manifestation as the three gunas — represented by Her three Saktis of Iccha (will), Jnana (knowledge), and Kriya (action) — and rays out as the 15 Nityas or Eternities who express the phases of the Moon or Candrakalas, and form the body of time.
According to the tradition, Shiva, without characteristics is awareness. And Shiva is one with Shakti. Her parts as represented by the Shodha Nyasa amount to 156, and comprise all visible manifestation. She is Maya Shakti, the Matrika or letters of the alphabet Devi, the heap of words and letters which delude men and women, and also those letters transformed by awareness into mantra.
Her yantra is the Shri Chakra, which contains all letters within its heap of petals, lotuses and lines. This yantra, which is a diagrammatic representation of the human body, is within the wheel of time.
Worship via this ritual is intended to assist a sadhvini or sadhaka to realise her or his oneness with the Shakti, with the yantra, and with time itself in all its manifestations.
Mahashodha Nyasa
In this wonderful abbreviated six way nyasa, obeisance to Dakshinamurti, the Rishi, on the head; to the metre Gayatri in the mouth; to the Devi Mahatripurasundari, to Ganeshas, Planets, (27) Sidereal Constellations, Yoginis, 12 Rashis, the Sacred Sites (pithas) in the heart; obeisance to the application of this Shri Vidya limb nyasa, in the palm of the hand.
Aim Hrim Shrim Am Kam Kham Gam Gham Nam Am Aim obeisance to the thumbs
Aim Hrim Shrim Im Cam Cham Jam Jham Nam Im Klim, index fingers
Aim Hrim Shrim Um Tam Tham Dam Dham Nam Um Sauh, middle fingers
Aim Hrim Shrim Em Tam Tham Dam Dham Nam Aim Aim, ring fingers
Aim Hrim Shrim Aum Pam Pham Bam Bham Mam Aum Klim, little fingers
Aim Hrim Shrim Am Yam Ram Lam Vain Sam Sam Sam Ham Lam Ksham Am Sauh, front & back of hand
(similarly for heart &c. nyasa)
Meditation
Radiant as 1000 rising suns, with full, magnificent breasts, wearing red garlands and clothes, smeared with red unguent, with red gems and red ornaments, holding goad, noose, bow and arrows in Her radiant four hands, with three beautiful eyes, with a gold ornament on Her head — thus we meditate on the Supreme Sundari, consisting of Ganeshas, Planets, (27) Nakshatras, (6) Yoginis, (12) Rashis, Pithas, and the letters of the alphabet.
Thus is declared the collective form of the Shri Devi, together with Her weapons and instruments of action. Now meditate on Ganeshas, the first of the individual forms:
Ganesha Nyasa
Meditation: resembling the newly risen Sun, with an elephant’s face, soft eyes, holding goad, noose, and granting boons, with Shakti, of vermilion lustre, decorated with all manner of gems. One of (her) hands holds a lotus, the other touches (Ganesha’s) lingam. His trunk is coiled to the left. When meditating, the noose comes first. The Shakti holds a lotus in Her left hand, and Her right hand embraces (Ganesha’s lingam).
Having meditated thus, nyasa should be done in the places where the letters of the alphabet reside, prefixing each with three syllables thus:
Aim Hrim Shrim Am obeisance to the Lord of Obstacles with Shri. On head.
Aim Hrim Shrim Am to the King of Obstacles with Hri. On forehead.
Aim Hrim Shrim Im to the Guide with Tushti. On right eye.
Aim Hrim Shrim Im to the Most Auspicious with Shanti. On left eye.
Aim Hrim Shrim Um to the Heart of Obstacles with Pushti. On right ear.
Aim Hrim Shrim Um to the Maker of Obstacles with Sarasvati. On left ear.
Aim Hrim Shrim Rm to the Chief of Obstacles with Rati. Right nostril.
Aim Hrim Shrim Rm to the Chief of Hosts with Medha. On left nostril.
Aim Hrim Shrim Lm to the One Tusked with Kanti. On right cheek.
Aim Hrim Shrim Lm to the Two Tusked with Kamini. On left cheek.
Aim Hrim Shrim Em to the Elephant Faced with Mohini. On upper lip.
Aim Hrim Shrim Aim to the Guileless with Jata. On lower lip.
Aim Hrim Shrim Om to the One with Hair Twisted like a Cowrie with Tivra. On upper teeth.
Aim Hrim Shrim Aum to the Long Faced with Jvalini. On lower teeth.
Aim Hrim Shrim Am to the One with Pointed Ears with Nanda. On tongue.
Aim Hrim Shrim Ah to the One with Bull as Banner with Surasa. On throat.
Aim Hrim Shrim Kam to the Lord of Numbers with Kamarupini. On right shoulder.
Aim Hrim Shrim Kham to Indra’s Elephant with Subhra. On right elbow.
Aim Hrim Shrim Gam to the One with Ears Like Winnowing Baskets with Jayini. R. wrist
Aim Hrim Shrim Gham to the three Eyed One with Satya. Base of right fingers.
Aim Hrim Shrim Nam to the Pot Bellied One with Vignneshi. On right finger tips.
Aim Hrim Shrim Cam to the Great Noisy One with Surupa. Left shoulder.
Aim Hrim Shrim Cham to the four Armed Form with Kamada. Left elbow.
Aim Hrim Shrim Jam to Sadashiva with Madavihvala. Left wrist.
Aim Hrim Shrim Jham to the Gladdening One with Vikata. Left root of fingers.
Aim Hrim Shrim Nam to the Ugly Faced with Puma. Left finger tips.
Aim Hrim Shrim Tam to the Beautiful Faced One with Bhutida. Right thigh.
Aim Hrim Shrim Tham to the Delightful One with Bhumi. Right knee.
Aim Hrim Shrim Dam to the One Footed with Shakti. Right ankle.
Aim Hrim Shrim Dham to the Dual Tongued with Rama. Right foot.
Aim Hrim Shrim Nam to the Hero with Manushi. Right toes.
Aim Hrim Shrim Tam to the Warrior with Makaradhvaja. Left thigh.
Aim Hrim Shrim Tham to the Peaceful Faced One with Virini. Left knee.
Aim Hrim Shrim Dam to the Boon Giver with Bhrukuti. Left ankle.
Aim Hrim Shrim Dham to the Left Hand God with Lajja. Left foot.
Aim Hrim Shrim Nam to the One with Crooked Trunk with Dirghagona. Left toes.
Aim Hrim Shrim Pam to the One with two Tusks with Dhanurdhara. Right side.
Aim Hrim Shrim Pham to the Leader of the Army with Yamini. Left side.
Aim Hrim Shrim Bam to the Village Lord with Ratri. Back.
Aim Hrim Shrim Bham to the Intoxicated One with Chandrika. Navel.
Aim Hrim Shrim Mam to the Clear Headed with Sashiprabha. Belly.
Aim Hrim Shrim Yam to Intoxication’s Vehicle with Lola. In heart.
Aim Hrim Shrim Ram to the Ascetic with Chapala. Right collar bone.
Aim Hrim Shrim Lam to the One with Shorn Hair with Riddhi. Shoulder hump.
Aim Hrim Shrim Vam to the One with a Tusk with Durbhaga. Left collar bone.
Aim Hrim Shrim Sham to the Pre-eminent One with Subhaga. Heart to right palm.
Aim Hrim Shrim Sham to the Bull Bannered with Shiva. Heart to left palm.
Aim Hrim Shrim Sam to the Greedy One with Durga. Heart to right foot.
Aim Hrim Shrim Ham to Ganesha with Kali. Heart to left foot.
Aim Hrim Shrim Lam to the One like Thunder with Kalakubjika. Heart to genitals.
Aim Hrim Shrim Ksham to the Lord of Obstacles with Destroyer of Obstacles. On heart.