You can simplify it a bit. Yes, gradual replacement is likely the way to go, but you probably don't need to replace individual neurons one at a time. Individual

You can simplify it a bit. Yes, gradual replacement is likely the way to go, but you probably don't need to replace individual neurons one at a time. Individual neurons don't really matter or meaningfully contribute to our consciousness. You can likely replace the large "functional groups" of neurons instead, with the group size threshold being the maximum that doesn't meaningfully affect our consciousness. This might well be many billions of neurons at a time.