how to install a second kernel on my system ?

I'd like to use webcam with fedora core 3.
Googling around the web, and searching for support, I found a How-to
giving guidelines for using webcams with fedora core 3.
It advises to get the sources of the kernel, that is on the system.
My current kernel version is , and unfortunately I can't
find kernel- neither on the web, and nor on the iso
images that I burnt one or two years ago .
So, I was thinking about adding a more recent kernel that I could
choose at boot-time.
Do you have some hints, or How-to to advise me ?
Is it simpler to change the whole distribution, or is it possible to
make coexist the old kernel and a newer one ?
Thanks for your help,