I have a computer. What makes my computer unique and different from anyone else's is the information that I save, i.e., programs, mp3's, pictures, etc. One day my computer will wear out, just like all material things do. But, the information that I have saved can live on. I can take the hard drive (brain) out and put it in another computer (body). Or, I can transfer the information, wirelessly, into another computer!
I believe that anyone reading this gets the idea that I am making. The important thing is the DATA (soul), NOT the computer (body). Now, I personally DO NOT believe in much of anything that the Watchtower teaches, and to be honest, I don't put a lot of stock into the Bible. Nevertheless, I most definitely DO believe in a higher source that created the earth and mankind. If man has devised a way to transfer information, wirelessly, into other objects, who's to say that a higher source cannot transfer the soul (information) into another body, whether it is a physical body or a spiritual body?
I don't know and I am not saying that what I have put forth is fact, I just throw it out there as a possibility.