The prayer to Manjushri, the Buddha of Wisdom, is recited by all the four schools of Tibetan Buddhism before starting the classes on all levels of teachings. It is said that there was a large conference in Nalanda University in India where more than 500 panditas (scholars) gathered. When they said prayers to Manjushri, this praise to him was simultaneously and spontaneously said by all the panditas. From then onwards this was used as the prayer to Manjushri by Mahayana Buddhist practitioners who were able to increase their power to learn and become great masters.
First we visualize Manjushri in the sky in front of us and repeat this prayer one time or three times or more depending on the time we have. Then we recite his root mantra for a while.
When closing the prayer we visualize that the light of Manjushri's supreme compassionate wisdom falls upon us and we receive the blessings which enrich our ability to learn the canons and their commentaries.
We don't have to have empowerment to say these prayers.
I prostrate before my guru and guardian,
Your intelligence shines forth like the sun,
Your affection for all of us masses who wander,
Its thunderous roar arouses us from the stupor
Pure from the core and having traversed the ten bhumis,
Please remove the darkness from my mind.
OM-A-RA-PA-TSA-NA-DHIH [repeat many times.]
DHIH-DHIH, DHIH-DHIH, DHIH-DHIH [repeat many times.]
Affectionate one, with light-rays of your supreme omniscience
Direct me, please, so that confident intelligence emerges within