Can we change one's genome into the genome of somebody else If I (grown-up individual and not just an egg after fertilization) wanted your exact genome, would we be able with today's technology to change my genome into yours?

There are 3.72x1013 (37 _trillion_ ) cells in the average adult human body. It would be essentially impossible to target every single cell just to change a single base pair, let alone the massive genetic and epigenetic changes that would be necessary to change someone into a clone of another.