Downgrading kernel?

[Oliver Ruebenacker]

     Dear friends,

  How do I downgrade to an older kernel, or to any older version of an
already installed package? I can not find an rpm or yum option to do
it, and I can not find a yum option to show anything but the newest
version of a package. Thanks!

     Take care
     Oliver

-- 
Oliver Ruebenacker, Post-Doc Researcher
Theoretical Biological Physics and Soft Statistical Mechanics
Cell Biology at UConn Health Center and Physics at Harvard
http://people.deas.harvard.edu/~oliver/