A Stand-in for Dying by Rick Moskovitz's

In a near future world on the brink of environmental catastrophe, a mysterious woman brokers an anonymous pact between two men for the older man to inhabit the younger man’s body when he dies in exchange for a fortune and access to vast knowledge. The consequences for both men evolve over the ensuing years, while the covert agency behind the mind swapping technology seeks to use it to rule the world. Their moral and emotional development is informed by the resourceful women who love them, one an accomplished journalist, the other a teacher who guides AI’s to feel emotions and advocates for them to have equal rights with carbon-based humans.