If you are still in the thinking stages of upgrading, then I'll assume you haven't actually done it yet, and if so, I'd agree with hob's advice and would likewise recommend doing a fresh reinstall. I have no first hand knowledge of trying to make a leap of that distance (6.2 to 9.0 is huge) but the prospect would be daunting, to say the least. If you did take the fresh reinstall route though, you could just avoid installing Gnome in the first place, and thus knock out any need for cleaning up after the fact.
I'll also second hob's comments regarding RH9 no longer being officially supported - that is (or at least should be) an important consideration given that there won't be any future security or maintenance patches. Personally, I would be inclined to consider using a distro that is being supported. On the other hand if you've been using 6.2 for the past several years, I will have to presume that the topic of keeping maintenance up to date is one that you are well acquainted with.
In any event good luck with it whatever decision you make. -- J.W.