Removing old kernels

[Shane Presley <shane presley gmail com>]

Hello,

I have a RHEL v3 server that's been around for awhile, and kept
up2date with kernel upgrades.

But I haven't been removing old kernels.  So /boot is filling up.  

How do I clean that up?  I know when the system boots I can remove
images.  But I'd like to do this without rebooting.  For any one image
there seem to be a ton of files. Do I just remove them?  I think I
have to also edit the grub.conf?

Maybe there's a command line way to do this in one step?  That would be nice :)

Thanks
Shane