changing a process's parent

Question

Is it possible to change a process parent?
ex: parent A has Child B can I make the parent of B is the Init process without killing A?

Answer 1

Not from outside of process B.

From inside process B, you can call fork which makes a copy of your process, then let the original exit. When that happens the new copy B2 will not be a child of A, its parent will be set to 1 (the init process).