How to edit a isolinux.cfg / isolinux.bin

Hi,

My plan is to boot Ubuntu 10.10 via an external Firewire drive on a Macbook 3.1

I am trying to create a boot CD based on instructions from an old thread here.

I not too sure if it would work still and the only latest information I came across outside the forums does not explain how to do it for a firewire drive.

I am stuck at editing the isolinux.bin file as I can't seem to open it in gedit. What software should I use to open this file? I changed the extension to .cfg and couldn't edit it either.