Many years ago, I started reading a science fiction book that involved robots with human minds uploaded into them. I say I “started reading” it, because early in the book, there was a scene where one of the characters, a teenaged or young adult woman, wanted to be a robot with eternal life, so she uploaded her mind to a robot and then leapt into a pool of lava.
I would hope her death was quick, but she did die. Unless you believe in mind/body duality and an incorporeal spirit that can magically flit from her body to the robot, that robot is not her. It may act like her, may even believe it is her, but it is not her. She died by suicide.
The story did not consider the fact that a young woman with her whole life ahead of her just committed suicide. It seemed to accept that she was now the robot, or that the robot was now her. That is why I didn’t finish the book. If you’re not going to think this through and approach it realistically, I’m not going to read your book.
I think there could be a way to make a human brain into a robot brain without killing the person, but it requires technology so advanced as to be indistinguishable from magic. I would say that you need nanobots programmed so that every night, as the human sleeps, the nanobots pick out neurons at random and replace them with perfect replicas, but they only replace, let’s say 1/1000 of the original neurons on each night. So it would take almost three years to completely replace every neuron, but at the end, the brain would be fully inorganic without the person’s consciousness ever having been disrupted.
If you just create that perfect replica in one go, pull out the organic brain, and slap in the replica, you’ve just killed the person, but a slow change over three years would be the same sort of change our bodies experience normally. I would read a story where that happened, but not one with people committing suicide so their robot replicas can take their places.