You can find the Genesis 2.0 changes by Googling them. I came across many myself just now.
Since Brian’s link isn’t working try this – http://www.carriedils.com/genesis-2-0-hooks/ There are plenty more out there as well.
Only replace what you see in your functions file….if you haven’t changed anything in your functions file, try swapping it out with the 1.3 version to save a lot of time. Same thing with the portfolio and home.php files. The css file is the only thing you’d need to manually convert if you’ve made changes.