just let it install and after its done take a win98 bootdisk with fdisk and boot from it; at the prompt type
and then reboot...lilo will be gone
you can download a win98 bootdisk from www.bootdisk.com
if you don't already have one.
p.s: make sure you make a linux bootdisk so that you can boot into linux.
edit: fixed the slash, thanks Thymox, sorry about that.