Actually, the rose was folded by Toshikazu Kawasaki hence the rose was named Kawasaki rose. The method of folding the rose has been modified and simplified by time and persons make me confused which one was the original one. But that that not an important issue as either one of it, it is still beautiful as you fold it in your own way.
I learn how to fold the rose from a japanese website by following the steps which clearly shown by detail photographs. Thank to the author, but i hope it will be available in english: Oribara web Just click on the button at the top with yellow origami rose and no 1.
Here are 2 videos from youtube to assist you to visualize the processes:
a stop motion video:
Advices: It is a very complex folding instructions and not for beginners. So if you are a beginner, do fold crane or lily first and proceed with the rose when you are ready to fold such a complex origami.
Please do try until you succeed, failure is not an option. If i can do it, you can too ;-) Good luck...