What is the ruling on someone who is named with a name whose origin is shirk (associating partners with Allah), such as the name "Bu'aysh," and is it obligatory to change this name despite the difficulty of the change procedures?

It is not permissible to be named with polytheistic names, such as عبد for other than Allah. There is no objection to naming children after righteous people, and there is no polytheism in that, and it is not necessary to change the name for one who has been named with it. It is not permissible to slaughter for one who is described as a "wali" (saint).