Bad update - X11 corrupted

[Dick Brown]

Hi all,
    I recently decided to upgrade from RH8 to Fedora.  I downloaded the 
.iso files, burned them and installed without a hitch (checked the 
md5sum and the finished CDs first).
    Unfortunately, when I performed the system update, the X11 package 
was corrupted.  Now I can't boot into Fedora normally.  I can get in 
through the "Linux rescue" from the install disk, but I'm afraid I don't 
know what to do from there.  I'm at that dangerous stage where I know 
enough to get myself into trouble, but not enough to get myself out, so 
I don't really want to touch anything without some advice first.  Is 
there an easy fix to this?

Thanks,
Dick