Does anyone know how to convert an LVM logical volume into a real partition, please?

(Why would I want to do this weird thing? Because it's my swap partition, and I want to be able to load suspend2 saved states from it without having to have an initrd.)

I've tried running swapoff -a, followed by the lvremove command within LVM, but LVM refuses to remove the partition, complaining that it's "open."

Thanks very much.