1. Boot from the cd/dvd media
2. type 'linux rescue' and [enter] at the boot: prompt
3. don't bother with networking config
3. allow the search for existing linux installs
4. when you have a bash prompt type 'chroot /mnt/sysimage'
# Assuming your problem is a forgotten password
5. type 'passwd'
6. enter new root password twice
Sorry, just re-read your Q, which files have you 'broken' ? You'll need to determine which package they belong to then force a reinstall. This can be done by copying the rpm's to /mnt/sysimage/var before step 4 or using '--root /mnt/sysimage' if you install from outside the chroot environment.
Last edited by kbp; 08-30-2010 at 01:34 AM.