What is the most promising method to replace all organs in the body?
a) Is it to use gene editing in combination with stem cells (eg. http://www.the-scientist.com/?articles.view/articleNo/46810/title/Using-CRISPR-to-Edit-Genes-in-Induced-Pluripotent-Stem-Cells/) to rejuvenate all organs or
b) is simply harvesting new organs through a backup body and replacing them all periodically the better approach.
c) combine human body parts with non human body parts to maximize lifespan (eg. use synthetic hearts, lungs, livers etc)
I think the likely best long term approach might be c).
However, the major challenge is preserving the brain, which would need to be backed up and perfectly copied to ensure the person was the “same”