Can you clarify what it is you don't understand?
If you're looking for an explanation of how to implement uploading, I can't be much help.
If you're looking for a way of having the idea seem more plausible: try reversing it. If I can replace neurons with hardware at all, why should it only be possible gradually, and why should it require destroying the original?
I can't wrap my head around what it would be like to exist as the "meat-version" and "cloud-version" at the same time if both of the versions maintain my identity. The reversal thing sort of makes me want to accept it more, but I wouldn't want to support the idea just because I personally don't know what would make those things limiting factors.
About gradualness: I can almost imagine that being important. Like, if you took baby!me and wrote over my mind with adult!me, maybe identity wouldn't be preserved... I guess that doesn't real...
Discuss things here if they don't deserve a post in Main or Discussion.
If a topic is worthy and receives much discussion, make a new thread for it.