HOW TO ELIMINATE LINUX KERNELS FROM LILO

I have several Linux boot options installed in my RedHat 7.3 LILO. how could I delete some of them?
When I run the RedHat update agent it shows that I hvae to increase my boot partition in at least 2MB. I think I can free some area from the boot partition by eliminating the kernells that I wont need any more.

Is it possible?