Update SuSE 7.2 to 8.2 via YaST?

Dear list, sorry if this question has been answered before, but I could not find any real answer on the achives. I have a SuSE 7.2 system and would like to upgrade to 8.2. Can I do this "online" just using YaST or YaST2? I do not have physical access to the system which is why I cannot boot from the 8.2 CD and upgrade "offline". Extra question: If this is not possible: What would be the difference between updating or manually updating the kernel and updating all packages via YaST? Torsten