There are two ways to rely upon Dorje Shugden: in thought and in deed.

If we recognize that Dorje Shugden is the embodiment of the Three Jewels; if we remember his kindness in protecting and preserving the Buddhadharma; if we recall how he eliminates obstacles and gathers the necessary conditions for Dharma practitioners; and if with deep faith we develop respect for him and hold these special feelings continually, we are relying upon Dorje Shugden in thought.

With deep faith and conviction in Dorje Shugden, we can practice his extensive, middling, or condensed sadhana. After completing a close retreat we can engage in peaceful, increasing, controlling and wrathful actions and gradually achieve the supreme attainments.

By engaging in these practices we can protect others by helping them to eliminate their obstacles and develop wisdom, to find the right conditions for practicing Dharma, to fulfil their wishes, and to meet with success in their daily lives. Whenever we engage in any of these deeds with faith we are relying upon Dorje Shugden in deed.

There are many commentaries, rituals, and sadhanas in relation to Dorje Shugden which were composed by high Sakya and Gelugpa Lamas.

For beings of this present age the late Trijang Dorjechang, who was the embodiment of Buddha Shakyamuni, Heruka, Atisha and Je Tsongkhapa, wrote his great commentary to Infinite Aeons, the praise to Dorje Shugden composed by Tagpo Kelsang Khedrub Rinpoche. He also wrote many special rituals and yogas for gaining different attainments connected with Dorje Shugden.

Source: Wisdom Buddha Dorje Shugden