While most people would think (including me) that yum reinstall kernel kernel-headers kernel-firmware would be enough, its not!  You need to select the one you wanne reinstall by removing it and then reinstalling it. (since its the only package that has multiple versions I guess)

For me this was :

# remove the evil
yum remove kernel-2.6.32-573.8.1.el6.x86_64 kernel-devel-2.6.32-573.8.1.el6.x86_64

# reinstall it again
# note : in my case I was oke with the "latest and newest" kernel
yum install kernel kernel-devel kernel-firmware

Happy kernel reinstalling ! (don’t think that a thing)