“Here we come to the power of entering another body.
Viz Adi Śaṅkara and King Vaṅgadeśa.
How is this achieved?
What is the cause of bondage to this body?

It is in the remainder of Karma, when that is finished there is freedom.
Thus the mind or Sūkṣma Śarīra which tansmigrates is different from the body.
It is the Liṅga or Sūkṣma Śarīra with the Vāsana and remainder of Karma.

How it is possible for the mind to remove itself prematurely by the right method?
First Karma must be understood.

Thus by the power of Saṃyama the Yogi works towards a loosening of the bondage of the body.

Another thing the Yogi will need to know is about the bodily functions controlled by the Pañca Vāyu.

Thus there are two Saṃyama here, one on the working of Karma or Vāsana on the mind and the other on the mind and the workings of the body and its subtle energies.

Having achieved this understanding the Yogi can take his mind out of his own body and deposit it into another body.
Whether the other body is dear or alive is speculative.
Raja Bhoja says it can be either.

This is similar to Nirmāṇa Citta where only the power of Asmitā is required to overcome another’s Citta and control it.”