How do a fix a non working kernel installation ?

[linux guy]

So... I found the koji site and I found a 2.6.31-rc3 kernel rpm for
 fc12.  It installed on my machine just fine with rpm -i.

 However, when I rebooted my computer all I got was a flashing cursor.
 No grub kernel select screen, no nothing.

 I am now running from a Fedora 9 live CD I had laying around.  I can
 see the hard drive and its partitions from the live session.  How
 would I fix the F11 installation so it runs again ?  Is it possible to
 do an rpm -e on the non running F11 partition from the F9 live session
 ?

 Thanks