[Wlug] RH 7.0->7.3 upgrade

I have four RH servers, two 7.0 and two new 7.3 servers just put up last 6 weeks or less How painless would an upgrade of the older servers from 7.0->7.3 be? Any surprises I should know about? Any comments or advice? I've never done a version upgrade before. I already have a CD with the most important security upgrades I used on the 7.3 servers after I had worm (Slapper/Cinik) problems. Dick Richard Goodman dick@goodman1.net