Syslinux - Oct 2014 - Replacing GRUB with SYSLINUX on an Ubuntu install ?

Hi, 


I have an exsiting Ubuntu install on a USB thumb-drive which uses GRUB2 as a
bootloader. Does anyone know if it is possible to replace GRUB with SYSLINUX and
if so, is there a step-by-step guide available anywhere? Anything I find on
Google seems to be geared towards creating a bootable drives from scratch as
opposed to replacing the bootloader on an existing install, can this be done ?


Thanks, 


Usjes.