You can use the powerful Debian GNU/Linux tool named apt-get. Your distribution is ready to work with it, just go to http://apt.freshrpms.net/
and install the rpm package of your Red Hat release.
When you're done with instaling apt-get type in your root console
#apt-get upgrade gnome
if you want your system beeng up to date just do
Remember, that first you must do apt-get update and than apt-get upgrade, but if you read the docs, you'll know what are you messing with
Hope this help
That's the easyest way I think.